Methods and Compositions for Treatment of Chlamydial Infection and Related Diseases and Disorders

ABSTRACT

The present invention provides compositions and methods of use in the treatment/prevention of chlamydial infection and/or diseases and disorders associated with chlamydial infection in a subject.

STATEMENT OF PRIORITY

This application claims the benefit, under 35 U.S.C. §119(e), of U.S.Provisional Application Ser. No. 61/877,898, filed Sep. 13, 2013, theentire contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to treatment/prevention of chlamydialinfection and diseases and disorders associated with Chlamydiainfection.

2. Background Art

Chlamydia is one of the most common sexually transmitted pathogens inthe world, causing an estimated 92 million infections per year, withover 2.8 million infections in the US alone. The rate for chlamydialinfection is 3.3 times higher in women than it is in men. It isestimated that nearly 3 million Americans are infected annuallycosting >$4 billion in healthcare. Most infected people have nosymptoms. However, untreated infections can cause numerous diseases suchas infertility, osteoporosis, reactive arthritis, Alzheimer's disease,pelvic inflammatory disease and others. In addition, numerousepidemiological studies have shown a positive association betweenChlamydia infections and the presence of premalignant or invasivecancers.

Currently there is no mechanism-based treatment of Chlamydia infectionsand Chlamydia-related diseases. Commonly used antibiotics can stop acuteinfections with Chlamydia; however, this treatment can also causeChlamydia to change into a persistent state, a stealth mode underlying achronic infection that can lead to Chlamydia associated diseases. Inaddition, during the last 30 years, attempts to create an effectiveChlamydia vaccine have proven unsuccessful. Thus, the identification ofchlamydial or host cell proteins that Chlamydia rely on for developmentin infected tissue is useful for development of effective therapeuticsagainst this pathogen.

The present invention overcomes previous shortcomings in the art byproviding methods and compositions employing inhibitors of epidermalgrowth factor receptor (EGFR) SUBSTITUTE SPECIFICATION CLEAN VERSION forthe treatment and/or prevention of chlamydial infection andChlamydia-associated diseases and disorders.

SUMMARY OF THE INVENTION

In one aspect the present invention provides a method of treatingchlamydial infection and/or treating and/or preventing a disease ordisorder caused by or associated with chlamydial infection in a subject,comprising administering to the subject an effective amount of aninhibitor of epidermal growth factor receptor (EGFR) expression and/oractivity.

In a further aspect, the present invention provides a method ofdelivering an agent of interest to a cell that expresses EGFR,comprising contacting the cell with a genetically modified Chlamydiaorganism comprising the agent of interest under conditions whereby theChlamydia organism binds the EGFR on the cell, thereby delivering theagent of interest to the cell.

In addition, the present invention provides a method of identifying asubstance that inhibits the binding of EGFR to F-actin, comprising: a)contacting the substance with EGFR and F-actin under conditions wherebybinding of EGFR and F-actin can occur; and b) assaying for the formationof an EGFR/F-actin binding complex, wherein the absence of formation ofan EGFR/F-actin binding complex identifies the substance as a substancethat inhibits the binding of EGFR to F-actin.

In another aspect, the present invention provides a method ofidentifying a subject as having an infection caused by Chlamydia or ashaving had an infection caused by Chlamydia, comprising: a) obtaining abiological sample from the subject; and b) assaying the sample of (a)for one or more proteins that are altered due to Chlamydia infection inthe subject; wherein altered is defined as a decrease or increase in theamount of the protein(s) of (b), and/or as a decrease or increase orchange in posttranslational modification (e.g., phosphorylation,oxidation, etc.) of the protein(s) and/or as a decrease or increase inactivity of the protein(s), and wherein detection of an alteration inthe protein(s) of (b) relative to a control (e.g., proteins assayed in abiological sample from a subject that does not have an infection causedby Chlamydia and/or that has not had an infection caused by Chlamydia)identifies the subject as having an infection caused by Chlamydia or ashaving had an infection caused by Chlamydia.

Additionally provided herein is a method of identifying a subject ashaving an increased likelihood of having or developing a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a biological sample from the subject; and b) assaying thesample of (a) for one or more proteins that are altered due to Chlamydiainfection in the subject; wherein altered is defined as a decrease orincrease in the amount of the protein(s) of (b), and/or as a decrease orincrease or change in posttranslational modification (e.g.,phosphorylation, oxidation, etc.) of the protein(s) and/or as a decreaseor increase in activity of the protein(s), and wherein detection of analteration in the protein(s) of (b) relative to a control identifies thesubject as having an increased likelihood of having or developing adisorder associated with infection caused by Chlamydia.

A further aspect of the present invention is a method of identifying asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated, comprising:a) obtaining a biological sample from the subject; and b) assaying thesample of (a) for one or more proteins that are altered due to Chlamydiainfection in the subject; wherein altered is defined as a decrease orincrease in the amount of the protein(s) of (b), and/or as a decrease orincrease or change in posttranslational modification (e.g.,phosphorylation, oxidation, etc.) of the protein(s) and/or as a decreaseor increase in activity of the protein(s), and wherein detection of analteration in the protein(s) of (b) relative to a control identifies thesubject as a subject for whom prophylactic treatment for a disease ordisorder associated with infection caused by Chlamydia is indicated.

The present invention also provides a method of guiding a treatmentregimen for a subject being treated for a disease or disorder associatedwith infection caused by Chlamydia, comprising: a) obtaining a firstbiological sample from the subject prior to or during treatment; b)assaying the first biological sample for one or more proteins that arealtered due to Chlamydia infection in the subject, wherein altered isdefined as a decrease or increase in the amount of the protein(s) of(b), and/or as a decrease or increase or change in posttranslationalmodification (e.g., phosphorylation, oxidation, etc.) of the protein(s)and/or as a decrease or increase in activity of the protein(s); c)obtaining a second biological sample from the subject at a subsequenttime point during treatment; d) assaying the second biological samplefor the same one or more proteins that are altered due to Chlamydiainfection in the subject; and e) comparing the altered proteins assayedin (b) with the amount and/or degree of alteration of the same alteredproteins assayed in (d), wherein a change in amount and/or degree of thealteration of the proteins assayed in (d) relative to the proteinsassayed in (b) indicates whether the treatment regimen should becontinued and/or increased or discontinued and/or decreased.

Furthermore, the present invention provides a method of identifying asubject as having an infection caused by Chlamydia or as having had aninfection caused by Chlamydia, comprising: a) obtaining a biologicalsample from the subject; and b) measuring in the sample of (a)methylation at specific DNA CpG sites that are altered due to Chlamydiainfection in the subject; wherein altered is defined as a decrease orincrease in the amount of methylation of (b) in the sample relative to acontrol, and wherein detection of alteration of methylation at specificDNA CpG sites relative to control identifies the subject as having aninfection caused by Chlamydia or as having had an infection caused byChlamydia.

In additional embodiments, the present invention provides a method ofidentifying a subject as having an increased likelihood of having ordeveloping a disease or disorder associated with infection caused byChlamydia, comprising: a) obtaining a biological sample from thesubject; and b) measuring in the sample of (a) methylation at specificDNA CpG sites that are altered due to Chlamydia infection in thesubject, wherein altered is defined as a decrease or increase in theamount of methylation of (b) in the sample relative to a control, andwherein detection of alteration of methylation at specific DNA CpG sitesrelative to control identifies the subject as having an increasedlikelihood of having or developing a disorder associated with infectioncaused by Chlamydia.

In addition, the present invention provides a method of identifying asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated, comprising:a) obtaining a biological sample from the subject; and b) measuring inthe sample of (a) methylation at specific DNA CpG sites that are altereddue to Chlamydia infection in the subject, wherein altered is defined asa decrease or increase in the amount of methylation of (b) in the samplerelative to a control and wherein detection of alteration of methylationat specific DNA CpG sites relative to control identifies the subject asa subject for whom prophylactic treatment for a disorder associated withinfection caused by Chlamydia is indicated.

As a further aspect, the present invention provides a method of guidinga treatment regimen for a subject being treated for a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a first biological sample from the subject prior to or duringtreatment; b) measuring in the first biological sample the amount ofmethylation at specific DNA CpG sites that are altered due to Chlamydiainfection in the subject; c) obtaining a second biological sample fromthe subject at a subsequent time point during treatment; d) measuring inthe second biological sample the amount of methylation at specific DNACpG sites that are altered due to Chlamydia infection in the subject;and e) comparing the amount of altered methylation as measured in (b)with the amount of altered methylation at the same sites as measured in(d), wherein a change in the amount of methylation measured in (d)relative to the amount of methylation measured in (b) indicates whetherthe treatment regimen should be continued and/or increased ordiscontinued and/or decreased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-G. EGFR is activated by C. trachomatis infection. (A) MEFsEGFR^(+/+) and MEFs EGFR^(−/−) cells were infected with C. trachomatis(Ct). Note the small chlamydial inclusions formed in the MEFs EGFR^(−/−)cells in comparison to the inclusions formed in MEFs EGFR^(+/+) cells.(B)-(F) Phosphorylation of EGFR in C. trachomatis-infected cells.Monolayers of MEFs EGFR^(+/+) (B) and HeLa (D) with and withoutchlamydial infection were lysed at different hours post-infection (hpi)as indicated and immunoblotted with antibodies against pY1173-EGFR andEGFR. The immunoblots from three independent experiments were quantifiedfor both MEFs (C) and HeLa cells (E) after normalization with β-actinused as loading control. A significant increase (P<0.05) inphosphorylation of EGFR in MEFs EGFR^(+/+) (C) and HeLa cells (E) wasobserved at 2.5 hpi. (F) HeLa cells with and without chlamydialinfection were lysed at 2.5 hpi. Two biological replicates weresubjected to immunoblotting for pPDGFRβ (Y751) and β-actin as loadingcontrol. An increase in PDGFRβ phosphorylation was observed in C.trachomatis-infected cells compared with non-infected cells. (G) MEFsEGFR^(+/+) were infected with C. trachomatis for 2.5 h or 5 h. Westernblotting was performed for comparing EGFR phosphorylation by C.trachomatis at various tyrosine residues. C. trachomatis inducedphosphorylation was observed at all sites analyzed with the exception ofY1148 site.

FIGS. 2A-C. C. trachomatis activates EGFR downstream signaling. (A)Monolayers of MEFs EGFR^(+/+) and (C) MEFs EGFR^(−/−) cells with andwithout chlamydial infection were lysed at 2.5, 5, 10 and 18 hpi. Celllysates were immunoblotted with antibodies against phosphorylated andtotal EGFR, PLCγ1, Akt and STAT5. β-actin was used as loading control.Each phosphorylated protein was first normalized against the totalprotein and then the fold increase from −Ct to +Ct was calculated fromthree independent experiments (B). An increased phosphorylation of EGFR,PLCγ1, Akt and STAT5 was observed in MEFs EGFR^(+/+) (P<0.05) while nochange was observed in the MEFs EGFR^(−/−) upon C. trachomatisinfection.

FIGS. 3A-E. C. trachomatis-induced activation ofPLCγ1, STAT5 and Akt isEGFR-dependent. (A-B) MEFs EGFR^(+/+) were treated with either scrambled(control) or EGFR siRNA and then infected with C. trachomatis. Cellswere lysed after 2.5 hpi and immunoblotted with antibodies againstphosphorylated and total PLCγ1, STAT5 and Akt (A). Western blots fromthree independent experiments were quantified (B). (C-E) HeLa and MEFsEGFR^(+/+) were treated with Cetuximab (an anti-EGFR antibody thatblocks the binding of EGF to EGFR, thus blocking receptor activation)followed by C. trachomatis infection. At 2.5 hpi the lysates wereimmunoblotted with antibodies against phosphorylated and total EGFR,PLCγ1, STAT5 and Akt (C). Western blots from three independentexperiments were quantified for both HeLa (D) and MEFs (E). C.trachomatis-induced phosphorylation of PLCγ1, STAT5 and Akt wascompletely or partially abrogated in cells that were either depleted ofEGFR (A-B; P<0.01) or treated with Cetuximab (C-E; P<0.05). β-actin wasused as loading control.

FIGS. 4A-H. EGFR is important for bacterial attachment and inclusiondevelopment. (A-B) Effect of EGFR inhibition on number and size ofinclusions. (A) HeLa cells treated with Erlotinib (a small moleculeinhibitor that targets the intracellular kinase domain of EGFR),Cetuximab, EGFR siRNA or PDGFRβ siRNA were infected with C. trachomatisfor 24 h, fixed, and analyzed by confocal microscopy and ImageJsoftware. Data from three independent experiments are expressed aspercentage of total number of inclusions (black bar) or inclusion size(gray bar) in comparison to the control. In each case the data werenormalized with the respective controls (DMSO, IgG or control siRNAtreated cells). The number of inclusions was significantly reduced inboth EGFR-inhibited (Erlotinib, Cetuximab or EGFR siRNA treated cells)as well as PDGFRβ depleted cells (P<0.01). Significant reduction in theinclusion size was observed only in the Erlotinib, Cetuximab and EGFRsiRNA treated cells (P<0.001) but not in PDGFRβ-depleted cells. (B) MEFsEGFR^(+/+) and MEFs EGFR^(−/−) were infected and processed as in (A).Significant reduction in both inclusion number and size was observed inMEFs EGFR^(−/−) (P<0.001) in comparison to the MEFs EGFR^(+/+) cells.Data are from three independent experiments. (C-D) Effect of EGFRinhibition on chlamydial attachment and entry into the host cell. HeLacells treated with Erlotinib, EGFR siRNA and PDGFRβ siRNA (C) orCetuximab (D), were infected with C. trachomatis for 2.5 h and insideout staining was performed to differentially stain both external andinternalized C. trachomatis. Data from three independent experiments areexpressed as number of cell-associated bacteria (external+internalizedC. trachomatis) and internalized C. trachomatis per infected host cell.Significant reduction in the chlamydial binding to the host cell surfacewas observed upon inhibition of both EGFR and PDGFRβ (P<0.05) incomparison to the C. trachomatis-infected control cells. (E-F) Levels ofchlamydial Hsp60 antigen. HeLa cells treated with Erlotinib, Cetuximab,EGFR siRNA or PDGFRβ siRNA were infected with C. trachomatis for 2.5 hand Western blotting was performed with anti-chlamydial Hsp60 antibody.Quantification of the Western blots from three independent experimentsshowed a significant (P<0.001) reduction in Hsp60 levels (F). β-actinwas used as loading control. In each case the data were normalized withthe respective controls (DMSO, IgG or control siRNA treated cells).(G-H) Transmission electron micrographs of HeLa cells infected with C.trachomatis. HeLa cells treated with Erlotinib (G) and Cetuximab (H),with respective controls, were infected with C. trachomatis for 24 h andfixed for transmission electron microscopy. Note the typical largeinclusions in the control chlamydial infected cells. In cells treatedwith Erlotinib and Cetuximab the inclusions are smaller and less mature.Scale Bar=2 mm.

FIGS. 5A-D. EGFR is essential for development of chlamydial inclusionpost-bacterial entry. (A-D) HeLa cells were infected with C. trachomatisfor 24 h. In panels B-D, EGFR inhibitor Erlotinib was added at 2.5, 5and 18 hpi, respectively. Under all conditions the total time for C.trachomatis infection was 24 h followed by fixing, and processing forconfocal microscopy. F-actin was detected with Alexa Fluor488-phalloidin and chlamydial inclusions were detected usinganti-chlamydial LPS antibody. Well-developed C. trachomatis inclusionswere observed in the DMSO treated cells (A) and in cells treated withErlotinib at 18 hpi (D); while incomplete inclusion development andbacterial aggregates were observed in cells treated with Erlotinib at2.5 hpi (B) and 5 hpi (C). F-actin staining of HeLa cells with Erlotinibtreatment but without C. trachomatis infection is shown in FIG. 21.Scale bar—10 mm.

FIGS. 6A-D. EGFR is required for C. trachomatis-induced calciummobilization. (A-B) Calcium mobilization induced by C. trachomatisinfection. HeLa cells treated with control siRNA, EGFR siRNA or PDGFRβsiRNA were infected with C. trachomatis for 2.5 h or 5 h and stainedwith Fluo-4 AM for visualization of calcium (Ca²⁺) by fluorescencemicroscopy. The fluorescence intensity of calcium staining from threeindependent experiments was quantified using ImageJ (B). Note the weakcalcium signal in EGFR inhibited cells (P<0.001) whereas in the case ofPDGFRβ inhibition the levels of calcium induced by C. trachomatis areequivalent as in control cells infected with C. trachomatis, indicatingthat EGFR is required for C. trachomatis-induced increase in calciumlevels. (C) Inclusion development and organization of F-actin at thechlamydial inclusion periphery. HeLa cells were pre-treated withBAPTA/AM (a calcium chelator) for 1 h followed by infection with C.trachomatis for 24 h, fixed, and processed for confocal microscopy. Datafrom three independent experiments were analyzed for number and size ofinclusions that were significantly reduced in BAPTA/AM treated cells(left panel). F-actin was detected with Alexa Fluor 488-phalloidin andchlamydial inclusions were detected using anti-chlamydial LPS antibody(right panel). Note the diffused assembly of F-actin at the inclusionperiphery (arrow). (D) Inclusion development in post infection BAPTA/AMtreated cells. HeLa cells were infected with C. trachomatis for 24 h.BAPTA/AM or control DMSO was added at 2 or 5 hpi. Under all conditionsthe total time for C. trachomatis infection was 24 h followed by fixing,and processing for confocal microscopy. F-actin was detected with AlexaFluor 488-phalloidin and chlamydial inclusions were detected usinganti-C. trachomatis EB antibody. Data are representative of twoindependent experiments. Note the impaired inclusion development inBAPTA/AM treated cells in comparison to the DMSO treated cells. F-actinstaining for HeLa cells with BAPTA/AM treatment but without C.trachomatis infection is also shown in FIG. 21. Scale bar—10 mm.

FIGS. 7A-E. EGFR is required for the reorganization of F-actin at theperiphery of chlamydial inclusions. (A-C) Organization of F-actin at thechlamydial inclusion periphery. HeLa cells treated with (A) controlsiRNA, (B) EGFR siRNA or (C) Erlotinib, were infected with C.trachomatis for 24 h, fixed, and processed for confocal microscopy.F-actin was detected with Alexa Fluor 488-phalloidin and chlamydialinclusions were detected using anti-chlamydial LPS antibody. Note thedistinct assembly of F-actin at the inclusion periphery in (A) which isaltered upon inhibition of EGFR (B-C). (D) HeLa cells treated with IgGor Cetuximab were infected with Ct for 24 h, fixed, and processed forconfocal microscopy. F-actin was detected with Alexa Fluor488-phalloidin and chlamydial inclusions were detected usinganti-chlamydial LPS antibody. Note the distinct assembly of F-actin atthe inclusion periphery in IgG treated cells and the lack of it inCetuximab treated cells. Scale bar—10 m. (E) Organization of F-actin atthe chlamydial inclusion periphery in MEFs EGFR^(+/+) and MEFsEGFR^(−/−). MEFs EGFR^(+/+) and MEFs EGFR^(−/−) were infected andprocessed as in (A). F-actin is noticeably rearranged at the chlamydialinclusion periphery in the MEFs EGFR^(+/+) but not in the MEFsEGFR^(−/−) cells.

FIGS. 8A-D. Co-localization of EGFR and F-actin at the periphery of C.trachomatis inclusion. (A) HeLa cells were infected with C. trachomatisfor 24 h, fixed and processed for confocal imaging to detect C.trachomatis, F-actin and EGFR. The merged image shows co-localization ofEGFR and F-actin. Dashed box represents the inclusion area, solid boxrepresents area and direction of intensity profile measurement in (C).Scale bars are 5 μm and 2 μm in whole cell and inclusion area images,respectively. (B) nMDP color maps showing heat maps of co-localizationareas in whole cell and inclusion area images. Both cell and inclusionboundaries show similar evidence of co-localization ranging frommoderate to intense. (C) Intensity profiles of C. trachomatis, EGFR, andF-actin from cell boundary to cell boundary across the inclusion. EGFRand F-actin signals rise and fall in similar patterns along theinclusion boundary (located at approximately 6 μm and 18 μm on thex-axis) indicating co-localization in a similar manner as at the cellboundary (located at approximately 3 μm and 21 μm on the x-axis). (D)Comparison of co-localization parameters between inclusion area imagesand non-inclusion area images (details in the legend for FIGS. 23-29).All five parameters show significant increase of co-localization ininclusion areas compared with non-inclusion areas. Data presentedrepresent the mean±standard deviation; n=8 μmages within each subset,***p<0.001.

FIG. 9. Proposed model of EGFR involvement at various stages of C.trachomatis infection. C. trachomatis infection induces EGFRphosphorylation and activation of downstream targets like Akt, STAT5 andPLCγ1. Activation of EGFR signaling can upregulate host cell survivalmechanisms and induce increased calcium mobilization. EGFRco-localization with F-actin is suggestive of a possible direct role ofEGFR in formation of F-actin rings at the periphery of inclusion. Theincreased calcium signaling can have several functions ranging fromcytoskeletal remodeling to recruitment of host proteins at the inclusionmembrane. The EGFR-induced formation of F-actin ring and othercytoskeletal elements at the inclusion periphery can further aid ininclusion expansion via vesicular trafficking and nutrient uptake.

FIG. 10. Western blot analysis of EGFR phosphorylation with Erlotinibtreatment. HeLa cells were treated with Erlotinib (15 μM, 25 μM)followed by Western blotting. Phosphorylation of EGFR was significantlyreduced in comparison to the untreated cells. β-actin was used asloading control.

FIG. 11. Western blot analysis of EGFR phosphorylation induced by Ctinfection in the absence or presence of Erlotinib treatment. HeLa cellswere treated with 25 μM Erlotinib for 2 h followed by the Ct infectionfor 2.5 h. Western blotting with pEGFR antibody showed an increase inEGFR phosphorylation upon Ct infection in the absence of Erlotinib butnot in the presence of the drug. β-actin was used as loading control.

FIG. 12. Western blot analysis of EGFR expression. HeLa cells weretreated with EGFR siRNA followed by Western blotting. siRNA treatmentsignificantly reduced the protein levels of EGFR by 70% in comparison tothe control siRNA treated cells. β-actin was used as loading control.This study also confirmed that expression of PDGFRβ remained unaffectedin EGFR siRNA treated cells.

FIG. 13. Western blot analysis of chlamydial Hsp60. HeLa cells weretreated with Erlotinib (25 μM) followed by Ct infection for 24 h.Western blotting with anti-chlamydial Hsp60 antibody showed markeddecrease in the Hsp60 antigen in the Erlotinib treated cells. β-actinwas used as loading control.

FIG. 14. Western blot analysis to test the viability of elementarybodies (EBs) treated with Erlotinib and Cetuximab. HeLa cells werepretreated with Erlotinib (25 μM) or Cetuximab (20 μg/ml) for 2.5 hfollowed by Ct infection for 24 h. Western blotting with anti-chlamydialHsp60 antibody showed no difference in the chlamydial Hsp60 antigen loadbetween the cells infected with either drug-treated or untreated EBs.β-actin was used as loading control.

FIG. 15. Cell viability assay. HeLa cells were treated with 25 M ofErlotinib for 24 h followed by the MTT assay (Roche). Erlotinibtreatment did not affect the viability of HeLa cells.

FIG. 16. Western blot analysis of PDGFRβ expression. HeLa cells weretreated with PDGFRβ siRNA followed by Western blotting. siRNA treatmentsignificantly reduced the protein levels of PDGFRβ in comparison to thecontrol siRNA treated cells. β-actin was used as loading control. It wasalso confirmed that expression of EGFR remained unaffected in PDGFRβsiRNA treated cells.

FIG. 17. Western blot analysis of EGFR in MEFs EGFR^(+/+) and MEFsEGFR^(−/−). EGFR was expressed only in MEFs EGFR^(+/+). β-actin was usedas loading control.

FIG. 18. Western blot analysis of chlamydial Hsp60. HeLa cells wereinfected with Ct and then treated with Erlotinib (25 μM) at either 2.5hpi or 18 hpi. The total time for Ct infection was 24 h followed byWestern blotting with anti-chlamydial Hsp60 antibody. Significantdecrease in the Hsp60 was observed in cells treated with Erlotinib at2.5 hours post Ct infection but not in cells treated with Erlotinab at18 hpi. β-actin was used as loading control.

FIGS. 19A-E. HeLa cells were infected with Ct for 24 h. In panels C-D,EGFR inhibitor Erlotinib was added at 2.5 and 5 hpi, respectively. Underall conditions the total time for Ct infection was 24 h and cells werestained with Fluo-4 AM for visualization of calcium (Ca²⁺) byfluorescence microscopy. (E) The fluorescence intensity of calciumstaining shown in panels A-D was quantified using Image J. Note the weakcalcium signal in EGFR inhibited cells (P<0.05) in comparison with cellsinfected with Ct in the absence of Erlotinib.

FIGS. 20A-B. Effect of lonomycin treatment on inclusion formation. (A)HeLa cells were treated with lonomycin (1 μg/ml) for 1 h and stainedwith Fura-2/AM for visualization of calcium (Ca²⁺) by fluorescencemicroscopy. Increased intracellular free calcium was observed withlonomycin treatment. (B) HeLa cells treated with EGFR siRNA with orwithout one hour pre-treatment with lonomycin (1 μg/ml) were infectedwith Ct for 24 h and fixed, and processed for confocal microscopy tocompare the inclusion formation in comparison to the Ct-infected controlcells. F-actin was detected with Alexa Fluor 488-phalloidin andchlamydial inclusions were detected using anti-chlamydial LPS antibody.In comparison to control, small inclusions were formed in the EGFRdepleted cells and no significant difference was observed between theinclusions formed in EGFR siRNA treated cells with or without lonomycintreatment. Scale bar—10 μm.

FIG. 21. F-actin staining in HeLa cells. F-actin staining was performedwith Alexa Fluor 488-phalloidin in HeLa cells treated with Erlotinib orBAPTA/AM. F-actin staining for untreated HeLa cells is also shown.

FIG. 22. Inclusion development in PDGFR siRNA treated cells. HeLa cellstreated with control siRNA or PDGFR siRNA were infected with C.trachomatis for 24 h, fixed, and processed for confocal microscopy.F-actin was detected with Alexa Fluor 488-phalloidin and chlamydialinclusions were detected using anti-chlamydial LPS antibody. Note thatsilencing PDGFR did not affect the size of the inclusion.

FIGS. 23A-D through FIG. 29. Comparison of cytofluorogram, Li's ICA, VanSteensel's CCF, and Costes' randomization analyses for EGFR and F-actinchannels of representative inclusion and non-inclusion area images andadditional algorithms used to generate data in FIG. 8D. Cytofluorogramsare generated to demonstrate the relationship between intensities ofeach color channel (EGFR—red; F-actin—green) at each pixel—a positiveslope greater than 0.5 and a tight scatter of data points indicatesco-localization of EGFR with F-actin. The increased slope of theinclusion cytofluorogram indicates higher colocalization of EGFR andF-actin than the non-inclusion image. This information was then utilizedto determine the Pearson's Coefficient. Li's Intensity CorrelationAnalysis (ICA) is performed to gain further insight into the degree ofco-localization. It calculates the difference from the mean channelintensity of each color at each pixel. Li's ICA analysis indicatesnoise-corrupted co-localization of EGFR and F-actin in the inclusionarea images as indicated by the points mostly falling on the positiveside of the x-axis. The non-inclusion area image is found to have almostno correlation between EGFR and F-actin as indicated by the pointsfalling roughly equally along the positive and negative sides of thex-axis. Li's ICA was also used here to determine Li's intensitycorrelation quotient (ICQ). Van Steensel's CCA is performed by shiftingone color channel in the x-direction pixel per pixel relative to theother channel and calculating the respective Pearson's Coefficient. Theresulting Pearson's Coefficients are then plotted as a function of thepixel shift. Bell-shaped data in Van Steensel's CCA indicatesco-localization and trough-shaped data indicates exclusion. VanSteensel's CCF analysis shows co-localization of EGFR and F-actin withunequal signal brightness in the inclusion area images and very weak,noise-corrupted partial overlap in the non-inclusion area images.Costes' randomization algorithm is performed to rule out the possibilitythat the observed co-localization of EGFR and F-actin is attributablesimply to random noise. Costes' randomization algorithm generates anumber of images populated by various amounts of noise in each colorchannel and calculates the Pearson's coefficient for each one(represented by the data points along the line). Costes' randomizationalgorithm shows that the Pearson's coefficients of both the inclusionarea images and the non-inclusion area image are due to signal ratherthan noise. Additional algorithm used in FIGS. 8 and 24-29: Thenormalized mean deviation product (nMDP) is calculated for each pixel inthe image to identify regions of intense co-localization or exclusionwithin the image. The nMDP analysis operates on the same basicprinciples as Li's ICA, except that pixel position information ismaintained, allowing the user to visualize where in the image thealgorithm has identified co-localization or exclusion. This algorithm isalso used here to determine the index of correlation (Icorr). Manders'coefficients are calculated to provide further insight into therelationship between EGFR and F-actin within each image. TheEGFR/F-actin Manders' coefficient is a measure of the percentage of EGFRsignal that is co-localized with F-actin signal. Conversely, theF-actin/EGFR Manders' coefficient is a measure of the percentage ofF-actin signal that is co-localized with EGFR signal.

FIG. 30. C. trachomatis-induced regulation of protein phosphorylation inJ774A.1 macrophages.

FIGS. 31A-B. Ingenuity Pathway Analysis of proteins that were up or downregulated in SQ-20B upon infection with C. trachomatis. A. Summary oftop functions. B. Protein mapping to G2/M checkpoint pathway.

FIG. 32. C. trachomatis induces ROS production in EGFR wt MEFs but notin EGFR KO MEFs.

FIG. 33. Anchorage-independent growth of Ct infected NIH 3T3 cells.Upper: Colony formation using soft agar assay. Bottom: Cell cycleanalysis of two transformed cell colonies picked from the soft agar.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is explained in greater detail below. Thisdescription is not intended to be a detailed catalog of all thedifferent ways in which the invention may be implemented, or all thefeatures that may be added to the instant invention. For example,features illustrated with respect to one embodiment may be incorporatedinto other embodiments, and features illustrated with respect to aparticular embodiment may be deleted from that embodiment. In addition,numerous variations and additions to the various embodiments suggestedherein will be apparent to those skilled in the art in light of theinstant disclosure, which do not depart from the instant invention.Hence, the following specification is intended to illustrate someparticular embodiments of the invention, and not to exhaustively specifyall permutations, combinations and variations thereof.

The present invention is based on the unexpected discovery thatepidermal growth factor receptor (EGFR) is involved in attachment anddevelopment of Chlamydia to and within, respectively, human cells duringchlamydial infection. Thus, in one embodiment, the present inventionprovides a method of treating chlamydial infection and/or treatingand/or preventing a disease or disorder caused by or associated withchlamydial infection in a subject, comprising administering to thesubject an effective amount of an inhibitor of epidermal growth factorreceptor (EGFR) expression and/or activity.

In the methods of this invention, the inhibitor of EGFR expressionand/or activity can be, but is not limited to, an antibody (e.g.,Cetuximab, Panitumumab, h-R3 (Nimotuzumab), EMD-72000 (Matuzumab),Zalutumab, MDX-447, mAb-806), a tyrosine kinase based inhibitor (e.g.,Erlotinib, Gefitinib, Lapatinib, Canertinib, vandetanib), an antisenseoligonucleotide based inhibitor (e.g., GEM231), FR18, an antibody orsmall molecule that targets the F-actin binding domain of EGFR, or anycombination of the above. Also included in this invention is any otherinhibitor of EGFR expression and/or activity now known or lateridentified.

In the methods of this invention, an agent that inhibits binding and/orinteraction of a Chlamydia organism with EGFR on a cell can also beemployed. Nonlimiting examples of an inhibitor of this binding orinteraction include an antibody or small molecule that targets achlamydial protein and prevents or interferes with the binding of aChlamydia organism to EGFR on a cell. Nonlimiting examples of aChlamydia protein that can be targeted for binding include a surfacemembrane protein (e.g., OmcB), a polymorphic membrane protein (Pmps),and/or a major outer membrane protein (MOMP).

Furthermore, nonlimiting examples of a disease or disorder caused by orassociated with chlamydial infection include cancer (e.g., lung, breast,cervical, head and neck, ovarian, etc.), infertility, osteoporosis,arthritis, Alzheimer's disease, pelvic inflammatory disease, asthma,atherosclerosis, chronic fatigue syndrome, chronic obstructive pulmonarydisease, coronary heart disease, metabolic syndrome, multiple sclerosis,myocardial infarction, stroke, Tourette syndrome, and any combinationthereof.

In some embodiments, the methods of this invention can further compriseadministering to the subject an antibiotic, a chemotherapeutic agent, ananti-inflammatory agent, an immunomodulatory agent and/or radiation, inany combination.

The present invention also provides a method of delivering an agent ofinterest to a cell that expresses EGFR, comprising contacting the cellwith a genetically modified Chlamydia organism comprising the agent ofinterest under conditions whereby the Chlamydia organism binds the EGFRon the cell, thereby delivering the agent of interest to the cell. By“genetically modified,” it is meant that the Chlamydia organism has beenmutated to render ii capable of infection of a cell but not capable offurther development in the cell; i.e., it is not pathogenic. In someembodiments, a nucleotide sequence encoding the agent of interest isintroduced into the mutant Chlamydia. Nonlimiting examples of an agentof interest of this invention include a nucleic acid molecule, aprotein, a drug, a small molecule, an imaging agent, a therapeutic agentand any combination thereof. As one nonlimiting example, geneticallymodified Chlamydia particles could be used for both sequential andsite-specific delivery technique. The Chlamydia particles first deliverTNF-related apoptosis-inducing ligand (TRAIL) to cancer cell membranes,e.g., to induce cell death and then penetrate the membrane to deliverthe chemotherapeutic doxorubicin (Dox) to the nucleus. The sequentialcombination of TRAIL and Dox may also produce an additive or synergisticeffect.

In further embodiments, the present invention provides a method ofidentifying a substance that inhibits the binding of EGFR to F-actin,comprising: a) contacting the substance with EGFR and F-actin underconditions whereby binding of EGFR and F-actin can occur; and b)assaying for the formation of an EGFR/F-actin binding complex, whereinthe absence of formation of an EGFR/F-actin binding complex identifiesthe substance as a substance that inhibits the binding of EGFR toF-actin. Such a substance can be employed in the methods of thisinvention as an inhibitor of EGFR activity.

As one nonlimiting example, the method of identifying a substance thatinhibits the binding of EGFR to F-actin can be an in vitro binding assayusing recombinant EGFR and actin. Actin polymerizes into F-actin invitro and can be separated from the soluble mixture by centrifugation.The ratio of soluble to F-actin bound EGFR can be used to quantify theinhibition of binding by substances of interest. This assay could becoupled with high-throughput screening of chemical libraries to find a“hit”; i.e., a chemical with an appropriate affinity to the EGFR-actinbinding domains that could be developed into a drug.

The present invention also provides a method of identifying a subject ashaving an infection caused by Chlamydia or as having had an infectioncaused by Chlamydia, comprising: a) obtaining a biological sample fromthe subject; and b) assaying the sample of (a) for one or more proteinsthat are altered due to Chlamydia infection in the subject; whereinaltered is defined as a decrease or increase in the amount of theprotein(s), and/or as a decrease or increase or change in theposttranslational modification of the protein(s) and/or as a decrease orincrease in activity of the protein(s), and wherein detection of analteration in the protein(s) relative to a control identifies thesubject as having an infection caused by Chlamydia or as having had aninfection caused by Chlamydia.

The present invention also provides a method of identifying a subject ashaving an increased likelihood of having or developing a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a biological sample from the subject; and b) assaying thesample of (a) for one or more proteins that are altered due to Chlamydiainfection in the subject; wherein altered is defined as a decrease orincrease in the amount of the protein(s) of (b), and/or as a decrease orincrease or change in its posttranslational modification (e.g.,phosphorylation, oxidation, etc.) and/or as a decrease or increase inactivity of the one or more proteins, and wherein detection of analteration in the protein(s) of (b) relative to a control identifies thesubject as having an increased likelihood of having or developing adisorder associated with infection caused by Chlamydia.

Additionally provided is a method of identifying a subject for whomprophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated, comprising: a) obtaining abiological sample from the subject; and b) assaying the sample of (a)for one or more proteins that are altered due to Chlamydia infection inthe subject; wherein altered is defined as a decrease or increase in theamount of the protein(s) of (b), and/or as a decrease or increase orchange in its posttranslational modification (e.g., phosphorylation,oxidation, etc.) and/or as a decrease or increase in activity of the onemore proteins, and wherein detection of an alteration in the protein(s)of (b) relative to a control identifies the subject as a subject forwhom prophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated. In some embodiments, thismethod can further comprise: c) providing prophylactic treatment to thesubject if the subject is identified in step (b) as a subject for whomprophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated; and d) not providingprophylactic treatment to the subject if the subject is not identifiedin step (b) as a subject for whom prophylactic treatment for a diseaseor disorder associated with infection caused by Chlamydia is indicated.

Additionally provided herein is a method of guiding a treatment regimenfor a subject being treated for a disease or disorder associated withinfection caused by Chlamydia, comprising: a) obtaining a firstbiological sample from the subject prior to or during treatment; b)assaying the first biological sample for one or more proteins that arealtered due to Chlamydia infection in the subject, wherein altered isdefined as a decrease or increase in the amount of the protein(s) of(b), and/or as a decrease or increase or change in its posttranslationalmodification (e.g., phosphorylation, oxidation, etc.) and/or as adecrease or increase in activity of the one or more proteins; c)obtaining a second biological sample from the subject at a subsequenttime point during treatment and/or after treatment; d) assaying thesecond biological sample for one or more proteins (e.g., the same one ormore proteins assayed in step (b)) that are altered due to Chlamydiainfection in the subject; and e) comparing the altered protein(s)assayed in (b) with the amount and/or degree of alteration of the samealtered protein(s) assayed in (d), wherein a decrease in the amountand/or degree of alteration of the protein(s) as assayed in the secondbiological sample as compared with the amount and/or degree ofalteration of the protein(s) as assayed in the first biological sampleindicates that the treatment regimen is imparting a positive orbeneficial effect and should be continued and/or increased and anincrease in the amount and/or degree of alteration of the protein(s) asassayed in the second biological sample as compared with the amountand/or degree of alteration of the protein(s) as assayed in the firstbiological sample indicates that the treatment regimen is not impartinga positive or beneficial effect and should be discontinued or reduced.

A nonlimiting example of a treatment regimen for a subject being treatedfor a disease or disorder associated with infection caused by Chlamydiainclude treatment with antibiotics, including but not limited toAzithromycin, Doxycyclin, Erythromycin base, Erythromycinethylsuccinate, Levofloxacin, and/or Ofloxacin, singly or in anycombination.

In the methods described above, the one or more proteins that arealtered due to Chlamydia infection can be, but are not limited to, EGFR,AKT, STAT3/5, PLCgamma, MKK4, ATR, cyclin B1, GADD45, MDM1, actin, p53,SIRT1-6, alpha-fetoprotein, apolipoprotein A-1, early growth response 1,peroxiredoxin 3, MK167 antigen identified by monoclonal antibody KI67,YWHAE, RbL1, heat shock protein 70 kDa (HSPA8), mitochondrial superoxidedismutase 2, endothelial nitric oxide synthase 3 and any combinationthereof.

In a further embodiment, the present invention provides a method ofidentifying a subject as having an infection caused by Chlamydia or ashaving had an infection caused by Chlamydia, comprising: a) obtaining abiological sample from the subject; and b) measuring in the sample of(a) methylation at specific DNA CpG sites that are altered due toChlamydia infection in the subject; wherein altered is defined as adecrease or increase in the amount of methylation of (b) in the samplerelative to a control (e.g., a sample from a subject that does not haveand/or has not had Chlamydia infection), and wherein detection ofalteration of methylation at specific DNA CpG sites relative to controlidentifies the subject as having an infection caused by Chlamydia or ashaving had an infection caused by Chlamydia.

The present invention also provides a method of identifying a subject ashaving an increased likelihood of having or developing a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a biological sample from the subject; and b) measuring in thesample of (a) methylation at specific DNA CpG sites that are altered dueto Chlamydia infection in the subject, wherein altered is defined as adecrease or increase in the amount of methylation of (b) in the samplerelative to a control, and wherein detection of alteration ofmethylation at specific DNA CpG sites relative to control identifies thesubject as having an increased likelihood of having or developing adisorder associated with infection caused by Chlamydia.

Also provided herein is a method of identifying a subject for whomprophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated, comprising: a) obtaining abiological sample from the subject; and b) measuring in the sample of(a) methylation at specific DNA CpG sites that are altered due toChlamydia infection in the subject, wherein altered is defined as adecrease or increase in the amount of methylation of (b) in the samplerelative to a control and wherein detection of alteration of methylationat specific DNA CpG sites relative to control identifies the subject asa subject for whom prophylactic treatment for a developing a disorderassociated with infection caused by Chlamydia is indicated. In someembodiments, this method can further comprise: c) providing prophylactictreatment to the subject if the subject is identified in step (b) as asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated; and d) notproviding prophylactic treatment to the subject if the subject is notidentified in step (b) as a subject for whom prophylactic treatment fora disease or disorder associated with infection caused by Chlamydia isindicated.

In addition, the present invention provides a method of guiding atreatment regimen for a subject being treated for a disease or disorderassociated with infection caused by Chlamydia, comprising: a) obtaininga first biological sample from the subject prior to or during treatment;b) measuring in the first biological sample the amount of methylation atspecific DNA CpG sites that are altered due to Chlamydia infection inthe subject; c) obtaining a second biological sample from the subject ata subsequent time point during treatment; d) measuring in the secondbiological sample the amount of methylation at specific DNA CpG sitesthat are altered due to Chlamydia infection in the subject; and e)comparing the amount of altered methylation in (b) with the amount ofaltered methylation at the same sites measured in (d), wherein adecrease in the amount of altered methylation sites measured in thesecond biological sample as compared with the amount of alteredmethylation sites measured in the first biological sample indicates thatthe treatment regimen is imparting a positive or beneficial effect andshould be continued and/or increased and an increase in the amount ofaltered methylation sites measured in the second biological sample ascompared with the amount of altered methylation sites measured in thefirst biological sample indicates that the treatment regimen is notimparting a positive or beneficial effect and should be discontinued orreduced. Nonlimiting examples of methylation sites include the promoterregion of genes such as STEAP3, FOXP1, C2orf76, LMAN1, SMARCC2, GPR133,FAM46A, ALCAM, TXNIP, LRCH3 and SP5, singly or in any combination.

In some embodiments, a method is provided of identifying a subject ashaving an infection caused by Chlamydia or as having had an infectioncaused by Chlamydia, comprising: a) obtaining a biological sample fromthe subject; and b) measuring in the sample of (a) the amount of one ormore proteins that are downregulated due to Chlamydia infection in thesubject; wherein a decrease in the amount of the protein(s) of (b) inthe sample relative to a control amount of the protein(s) identifies thesubject as having an infection caused by Chlamydia or as having had aninfection caused by Chlamydia.

In some embodiments, the present invention provides a method ofidentifying a subject as having an increased likelihood of having ordeveloping a disease or disorder associated with infection caused byChlamydia, comprising: a) obtaining a biological sample from thesubject; and b) measuring in the sample of (a) the amount of one or moreproteins that are downregulated due to Chlamydia infection in thesubject, wherein a decrease in the amount of the protein(s) of (b) inthe sample relative to a control amount of protein(s) identifies thesubject as having an increased likelihood of having or developing adisorder associated with infection caused by Chlamydia.

Furthermore, the present invention provides a method of identifying asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated, comprising:a) obtaining a biological sample from the subject; and b) measuring inthe sample of (a) the amount of one or more proteins that aredownregulated due to Chlamydia infection in the subject, wherein adecrease in the amount of the protein(s) of (b) in the sample relativeto a control amount of protein(s) identifies the subject as a subjectfor whom prophylactic treatment for a developing a disorder associatedwith infection caused by Chlamydia is indicated.

In additional embodiments, the present invention provides a method ofguiding a treatment regimen for a subject being treated for a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a first biological sample from the subject prior to or duringtreatment; b) measuring in the first biological sample the amount of oneor more proteins that are downregulated due to Chlamydia infection inthe subject; c) obtaining a second biological sample from the subject ata subsequent time point during treatment; d) measuring in the secondbiological sample the amount of the one or more proteins that aredownregulated due to Chlamydia infection in the subject; and e)comparing the amount of the protein(s) measured in (b) with the amountof the protein(s) measured in (d), wherein an increase in the amount ofthe protein(s) measured in (d) relative to the amount of the protein(s)measured in (b) indicates that the treatment regimen should be continuedor increased and a further decrease or limited change in the amount ofthe protein(s) measured in (d) relative to the amount of the protein(s)measured in (b) indicates that the treatment regimen should bediscontinued.

In the methods described above regarding a protein that is downregulateddue to Chlamydia infection, the protein can be, but is not limited toMKK4, ATR, cyclin B1, GADD45, MDM1, alpha-fetoprotein, apolipoproteinA-1, early growth response 1, peroxiredoxin 3, MK167 antigen identifiedby monoclonal antibody K167 and any combination thereof.

In yet further embodiments, the present invention provides a method ofidentifying a subject as having an infection caused by Chlamydia or ashaving had an infection caused by Chlamydia, comprising: a) obtaining abiological sample from the subject; and b) measuring in the sample of(a) the amount of one or more proteins that are upregulated due toChlamydia infection in the subject, wherein an increase in the amount ofthe protein(s) of (b) in the sample relative to a control amount of theprotein(s) (e.g., an amount of the protein(s) in a sample from a subjectthat does not have and/or has not had a Chlamydia infection) identifiesthe subject as having an infection caused by Chlamydia or as having hadan infection caused by Chlamydia.

Further provided herein is a method of identifying a subject as havingan increased likelihood of having or developing a disease or disorderassociated with infection caused by Chlamydia, comprising: a) obtaininga biological sample from the subject; and b) measuring in the sample of(a) the amount of one or more proteins that are upregulated due toChlamydia infection in the subject, wherein an increase in the amount ofthe protein(s) of (b) in the sample relative to a control amount ofprotein(s) identifies the subject as having an increased likelihood ofhaving or developing a disorder associated with infection caused byChlamydia.

In addition, the present invention provides a method of identifying asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated, comprising:a) obtaining a biological sample from the subject; and b) measuring inthe sample of (a) the amount of one or more proteins that areupregulated due to Chlamydia infection in the subject, wherein anincrease in the amount of the protein(s) of (b) in the sample relativeto a control amount of protein(s) identifies the subject as a subjectfor whom prophylactic treatment for a developing a disorder associatedwith infection caused by Chlamydia is indicated.

A further embodiment of this invention includes a method of guiding atreatment regimen for a subject being treated for a disease or disorderassociated with infection caused by Chlamydia, comprising: a) obtaininga first biological sample from the subject prior to or during treatment;b) measuring in the first biological sample the amount of one or moreproteins that are upregulated due to Chlamydia infection in the subject;c) obtaining a second biological sample from the subject at a subsequenttime point during treatment; d) measuring in the second biologicalsample the amount of the one or more proteins that are upregulated dueto Chlamydia infection in the subject; and e) comparing the amount ofthe protein(s) measured in (b) with the amount of the protein(s)measured in (d), wherein a decrease in the amount of the protein(s)measured in (d) relative to the amount of the protein(s) measured in (b)indicates that the treatment regimen is imparting a positive and/orbeneficial effect should be continued or increased, and an increase orlimited change in the amount of the protein(s) measured in (d) relativeto the amount of the protein(s) measured in (b) indicates that thetreatment regimen is not imparting a positive or beneficial effect andshould be discontinued or decreased.

In the methods described above regarding a protein that is upregulateddue to Chlamydia infection, the protein can be, but is not limited to,EGFR, AKT2, PLCγ1, STAT5, YWHAE, RbL1, heat shock protein 70 kDa(HSPA8), mitochondrial superoxide dismutase 2, endothelial nitric oxidesynthase 3, and any combination thereof.

In the methods described above, measuring downregulation or upregulationof a protein and/or assaying a sample for a protein that is altered dueto Chlamydia infection can be carried out by using protocols thatmeasure the amount of the protein itself, protocols that measure theamount of activity of the protein, protocols that measure thecharacteristics of the protein (e.g., phosphorylation, oxidation state,etc.), protocols that measure the amount of messenger RNA that encodesthe protein, protocols that measure expression of DNA that encodes theprotein, etc., either singly or in any combination, all of which areprotocols that are well known in the art.

A further embodiment of this invention includes a method of reducing thelikelihood of infertility due to Chlamydia infection in a subject,comprising administering to the subject an effective amount of aninhibitor of epidermal growth factor receptor (EGFR) expression and/oractivity.

By “reducing the likelihood of infertility due to Chlamydia infection”is meant that a subject of this invention to whom the compositions ofthis invention are administered is less likely to become infertile as aresult of being infected by Chlamydia as compared to the likelihood thatan untreated subject will become infertile as a result of being infectedby Chlamydia. That infertility is prevented or its likelihood as aresult of Chlamydia infection is reduced in a subject can be determinedaccording to protocols well known in the art.

In some embodiments of the methods of this invention, the disease ordisorder associated with infection caused by Chlamydia can be cancer ora precancerous condition. Nonlimiting examples of a cancer of thisinvention include B cell lymphoma, T cell lymphoma, myeloma, leukemia,hematopoietic neoplasias, thymoma, lymphoma, sarcoma, lung cancer, livercancer, non-Hodgkins lymphoma, Hodgkins lymphoma, uterine cancer,adenocarcinoma, breast cancer, pancreatic cancer, colon cancer, lungcancer, renal cancer, bladder cancer, liver cancer, prostate cancer,ovarian cancer, primary or metastatic melanoma, squamous cell carcinoma,basal cell carcinoma, brain cancer, angiosarcoma, hemangiosarcoma, headand neck carcinoma, thyroid carcinoma, soft tissue sarcoma, bonesarcoma, testicular cancer, uterine cancer, cervical cancer,gastrointestinal cancer, and any other cancer now known or lateridentified (see, e.g., Rosenberg (1996) Ann. Rev. Med. 47:481-491, theentire contents of which are incorporated by reference herein).

In certain embodiments, employing the methods of this invention providesa reduction in the incidence of hydrosalpinx, oviduct dilatation, and/orcellular infiltration associated with chlamydial infection. Thus, thepresent invention further provides methods of treating and/or preventinghydrosalpinx, oviduct dilatation, and/or cellular infiltrationassociated with chlamydial infection in a subject, comprisingadministering to the subject an effective amount of an inhibitor of EGFRexpression and/or activity.

DEFINITIONS

As used herein, “a,” “an” or “the” can mean one or more than one. Forexample, “a” cell can mean a single cell or a multiplicity of cells.

Also as used herein, “and/or” refers to and encompasses any and allpossible combinations of one or more of the associated listed items, aswell as the lack of combinations when interpreted in the alternative(“or”).

Furthermore, the term “about,” as used herein when referring to ameasurable value such as an amount of a compound or agent of thisinvention, dose, time, temperature, and the like, is meant to encompassvariations of ±20%, ±10%, +5%, +1%, ±0.5%, or even ±0.1% of thespecified amount.

As used herein, the term “consists essentially of” (and grammaticalvariants) means that an immunogenic composition of this inventioncomprises no other material immunogenic agent other than the indicatedagents. The term “consists essentially of” does not exclude the presenceof other components in the composition such as adjuvants,immunomodulators, and the like.

The term “disease or disorder associated with infection caused byChlamydia” means that infection with Chlamydia was completely or partlyresponsible for the onset of disease or of the disorder. In some cases,the Chlamydia might still be present in the infected tissue; in others,the Chlamydia has been cleared or has switched to a persistent stateafter the initiation of disease or the disorder.

The terms “increased risk” and “decreased risk” as used herein definethe level of risk that a subject has of developing a disease or disorderassociated with infection by Chlamydia, as compared to a control subjectthat does not have the biomarkers of this invention.

A sample of this invention can be any sample containing protein and/ornucleic acid of a subject, as would be well known to one of ordinaryskill in the art. Nonlimiting examples of a sample of this inventioninclude a cell, a body fluid, a tissue, biopsy material, a washing, aswabbing, etc., as would be well known in the art.

A “subject” of this invention includes any animal susceptible toinfection by a Chlamydia species. Such a subject can be a mammal (e.g.,a laboratory animal such as a rat, mouse, guinea pig, rabbit, primates,etc.), a farm or commercial animal (e.g., a cow, horse, goat, donkey,sheep, etc.), a domestic animal (e.g., cat, dog, ferret, etc.), an avianspecies and in particular embodiments, is a human. A “subject in needthereof” is a subject known to be, or suspected of being, infected with,or at risk of being infected with, Chlamydia. A subject of thisinvention can also include a subject not previously known or suspectedto be infected by Chlamydia or in need of treatment for Chlamydiainfection. For example, a subject of this invention can be administeredthe compositions of this invention even if it is not known or suspectedthat the subject is infected with Chlamydia (e.g., prophylactically). Asubject of this invention is also a subject known or believed to be atrisk of infection by Chlamydia.

The species of Chlamydia encompassed by this invention include Chlamydiatrachomatis, Chlamydia muridarum, Chlamydia pneumoniae, Chlamydiapsittaci, Chlamydophila abortus, and/or Chlamydia caviae in anycombination.

The terms “prevent,” “preventing,” and “prevention” and like terms areused herein to include imparting any level of prevention or protectionwhich is of some benefit to a subject, such that there is a reduction inthe incidence and/or the severity of the disease in a treated subject,regardless of whether the protection or reduction in incidence and/orseverity is partial or complete.

The terms “reduce,” “reduced,” “reducing,” and “reduction” (andgrammatical variations thereof), as used herein, describe a decrease ina chlamydial infection- or disease-related parameter or symptom that isof some therapeutic value or benefit to the subject.

Also as used herein, the terms “treat,” “treating” or “treatment” referto any type of action that imparts a modulating effect, which, forexample, can be a beneficial and/or therapeutic effect, to a subjectafflicted with a condition, disorder, disease or illness, including, forexample, improvement in the condition of the subject (e.g., in one ormore symptoms), delay in the progression of the disorder, disease orillness, delay of the onset of the disease, disorder, or illness, and/orchange in clinical parameters of the condition, disorder, disease orillness, etc., as would be well known in the art.

“Effective amount” refers to an amount of a compound or composition ofthis invention that is sufficient to produce a desired effect, which canbe a therapeutic and/or beneficial effect. The effective amount willvary with the age, general condition of the subject, the severity of thecondition being treated, the particular agent administered, the durationof the treatment, the nature of any concurrent treatment, thepharmaceutically acceptable carrier used, and like factors within theknowledge and expertise of those skilled in the art. As appropriate, an“effective amount” in any individual case can be determined by one ofordinary skill in the art by reference to the pertinent texts andliterature and/or by using routine experimentation. (See, for example,Remington, The Science And Practice of Pharmacy (20th ed. 2000)).

Pharmaceutical Compositions

Pharmaceutical compositions comprising a composition of this inventionand a pharmaceutically acceptable carrier are also provided. Thecompositions described herein can be formulated for administration in apharmaceutical carrier in accordance with known techniques. See, e.g.,Remington, The Science And Practice of Pharmacy (latest edition). In themanufacture of a pharmaceutical composition according to embodiments ofthe present invention, the composition of this invention is typicallyadmixed with, inter alia, a pharmaceutically acceptable carrier. By“pharmaceutically acceptable carrier” is meant a carrier that iscompatible with other ingredients in the pharmaceutical composition andthat is not harmful or deleterious to the subject. The carrier may be asolid or a liquid, or both, and is preferably formulated with thecomposition of this invention as a unit-dose formulation, for example, atablet, which may contain from about 0.01 or 0.5% to about 95% or 99% byweight of the composition. The pharmaceutical compositions are preparedby any of the well-known techniques of pharmacy including, but notlimited to, admixing the components, optionally including one or moreaccessory ingredients.

The pharmaceutical compositions of this invention include those suitablefor oral, rectal, topical, inhalation (e.g., via an aerosol) buccal(e.g., sub-lingual), vaginal, parenteral (e.g., subcutaneous,intramuscular, intradermal, intraarticular, intrapleural,intraperitoneal, intracerebral, intraarterial, or intravenous), topical(i.e., both skin and mucosal surfaces, including airway surfaces) andtransdermal administration, although the most suitable route in anygiven case will depend, as is well known in the art, on such factors asthe species, age, gender and overall condition of the subject, thenature and severity of the condition being treated and/or on the natureof the particular composition (i.e., dosage, formulation) that is beingadministered.

Pharmaceutical compositions suitable for oral administration can bepresented in discrete units, such as capsules, cachets, lozenges, ortables, each containing a predetermined amount of the composition ofthis invention; as a powder or granules; as a solution or a suspensionin an aqueous or non-aqueous liquid; or as an oil-in-water orwater-in-oil emulsion. Oral delivery can be performed by complexing acomposition of the present invention to a carrier capable ofwithstanding degradation by digestive enzymes in the gut of an animal.Examples of such carriers include plastic capsules or tablets, as knownin the art. Such formulations are prepared by any suitable method ofpharmacy, which includes the step of bringing into association thecomposition and a suitable carrier (which may contain one or moreaccessory ingredients as noted above). In general, the pharmaceuticalcomposition according to embodiments of the present invention areprepared by uniformly and intimately admixing the composition with aliquid or finely divided solid carrier, or both, and then, if necessary,shaping the resulting mixture. For example, a tablet can be prepared bycompressing or molding a powder or granules containing the composition,optionally with one or more accessory ingredients. Compressed tabletsare prepared by compressing, in a suitable machine, the composition in afree-flowing form, such as a powder or granules optionally mixed with abinder, lubricant, inert diluent, and/or surface active/dispersingagent(s). Molded tablets are made by molding, in a suitable machine, thepowdered compound moistened with an inert liquid binder.

Pharmaceutical compositions suitable for buccal (sub-lingual)administration include lozenges comprising the composition of thisinvention in a flavored base, usually sucrose and acacia or tragacanth;and pastilles comprising the composition in an inert base such asgelatin and glycerin or sucrose and acacia.

Pharmaceutical compositions of this invention suitable for parenteraladministration can comprise sterile aqueous and non-aqueous injectionsolutions of the composition of this invention, which preparations arepreferably isotonic with the blood of the intended recipient. Thesepreparations can contain anti-oxidants, buffers, bacteriostats andsolutes, which render the composition isotonic with the blood of theintended recipient. Aqueous and non-aqueous sterile suspensions,solutions and emulsions can include suspending agents and thickeningagents. Examples of non-aqueous solvents are propylene glycol,polyethylene glycol, vegetable oils such as olive oil, and injectableorganic esters such as ethyl oleate. Aqueous carriers include water,alcoholic/aqueous solutions, emulsions or suspensions, including salineand buffered media. Parenteral vehicles include sodium chloridesolution, Ringer's dextrose, dextrose and sodium chloride, lactatedRinger's, or fixed oils. Intravenous vehicles include fluid and nutrientreplenishers, electrolyte replenishers (such as those based on Ringer'sdextrose), and the like. Preservatives and other additives may also bepresent such as, for example, antimicrobials, anti-oxidants, chelatingagents, and inert gases and the like.

The compositions can be presented in unit\dose or multi-dose containers,for example, in sealed ampoules and vials, and can be stored in afreeze-dried (lyophilized) condition requiring only the addition of thesterile liquid carrier, for example, saline or water-for-injectionimmediately prior to use.

Extemporaneous injection solutions and suspensions can be prepared fromsterile powders, granules and tablets of the kind previously described.For example, an injectable, stable, sterile composition of thisinvention in a unit dosage form in a sealed container can be provided.The composition can be provided in the form of a lyophilizate, which canbe reconstituted with a suitable pharmaceutically acceptable carrier toform a liquid composition suitable for injection into a subject. Theunit dosage form can be from about 1 g to about 10 grams of thecomposition of this invention. When the composition is substantiallywater-insoluble, a sufficient amount of emulsifying agent, which isphysiologically acceptable, can be included in sufficient quantity toemulsify the composition in an aqueous carrier. One such usefulemulsifying agent is phosphatidyl choline.

Pharmaceutical compositions suitable for rectal administration arepreferably presented as unit dose suppositories. These can be preparedby admixing the composition with one or more conventional solidcarriers, such as for example, cocoa butter and then shaping theresulting mixture.

Pharmaceutical compositions of this invention suitable for topicalapplication to the skin preferably take the form of an ointment, cream,lotion, paste, gel, spray, aerosol, or oil. Carriers that can be usedinclude, but are not limited to, petroleum jelly, lanoline, polyethyleneglycols, alcohols, transdermal enhancers, and combinations of two ormore thereof. In some embodiments, for example, topical delivery can beperformed by mixing a pharmaceutical composition of the presentinvention with a lipophilic reagent (e.g., DMSO) that is capable ofpassing into the skin.

Pharmaceutical compositions suitable for transdermal administration canbe in the form of discrete patches adapted to remain in intimate contactwith the epidermis of the subject for a prolonged period of time.Compositions suitable for transdermal administration can also bedelivered by iontophoresis (see, for example, Pharmaceutical Research3:318 (1986)) and typically take the form of an optionally bufferedaqueous solution of the composition of this invention.

An effective amount of a composition of this invention, the use of whichis in the scope of present invention, will vary from composition tocomposition, and subject to subject, and will depend upon a variety ofwell known factors such as the age and condition of the patient and theform of the composition and route of delivery. An effective amount canbe determined in accordance with routine pharmacological proceduresknown to those skilled in the art. For example, a dosage range foradministration of a protein (e.g., an antibody) to a subject inaccordance with the methods of this invention can be from about 100mg/day to about 1000 mg/day. Some nonlimiting examples, includeErlotinib, having a dosage range of about 100-150 mg orally once a day;Cetuximab, having a dosage range of about 100-200 mg once a day byintravenous infusion; and Vectibix, having a recommended dose of about 6mg/kg, administered as an intravenous infusion over 60 minutes. Doseshigher than 1000 mg should be administered over 90 minutes.

The frequency of administration of a composition of this invention canbe as frequent as necessary to impart the desired therapeutic effect.For example, the composition can be administered one, two, three, fouror more times per day, one, two, three, four or more times a week, one,two, three, four or more times a month, one, two, three or four times ayear or as necessary to control the condition. In some embodiments, one,two, three or four doses over the lifetime of a subject can be adequateto achieve the desired therapeutic effect. The amount and frequency ofadministration of the composition of this invention will vary dependingon the particular condition being treated or to be prevented and thedesired therapeutic effect.

The compositions of this invention can be administered to a cell of asubject either in vivo or ex vivo. For administration to a cell of thesubject in vivo, as well as for administration to the subject, thecompositions of this invention can be administered, for example as notedabove, orally, parenterally (e.g., intravenously), by intramuscularinjection, intradermally (e.g., by gene gun), by intraperitonealinjection, subcutaneous injection, transdermally, extracorporeally,topically or the like. Also, the composition of this invention may bepulsed onto dendritic cells, which are isolated or grown from patientcells, according to methods well known in the art, or onto bulk PBMC orvarious cell subfractions thereof from a patient.

If ex vivo methods are employed, cells or tissues can be removed andmaintained outside the body according to standard protocols well knownin the art while the compositions of this invention are introduced intothe cells or tissues. For example, the nucleic acids and vectors of thisinvention can be introduced into cells via any gene transfer mechanism,such as, for example, virus-mediated gene delivery, calcium phosphatemediated gene delivery, electroporation, microinjection orproteoliposomes. The transduced cells can then be infused (e.g., in apharmaceutically acceptable carrier) or transplanted back into thesubject per standard methods for the cell or tissue type. Standardmethods are known for transplantation or infusion of various cells intoa subject. Thus, in one embodiment of this invention, the chimericpolypeptide comprising the recall antigen and new antigen of thisinvention can be presented to the immune system in a subject on thesurface of a cell (i.e., as a cell surface antigen present in the plasmamembrane of the cell) and in other embodiments can be presented to theimmune system in a subject as a non-cell associated (i.e., cell-free)chimeric polypeptide.

Administration of the nucleic acids of this invention can be achieved byany one of numerous, well-known approaches, for example, but not limitedto, direct transfer of the nucleic acids, in a plasmid or viral vector,or via transfer in cells or in combination with carriers such ascationic liposomes. Such methods are well known in the art and readilyadaptable for use in the methods described herein. Furthermore, thesemethods can be used to target certain diseases and cell populations byusing the targeting characteristics of the carrier, which would be wellknown to the skilled artisan.

Transfer vectors employed in the methods of this invention can be anynucleotide construct used to deliver nucleic acid into cells, e.g., aplasmid or viral vector, such as a retroviral vector which can package arecombinant retroviral genome (see e.g., Pastan et al., Proc. Natl.Acad. Sci. U.S.A. 85:4486 (1988); Miller et al., Mol. Cell. Biol. 6:2895(1986)). The recombinant retrovirus can then be used to infect andthereby deliver a nucleic acid of the invention to the infected cells.The exact method of introducing the altered nucleic acid into mammaliancells is, of course, not limited to the use of retroviral vectors. Othertechniques are widely available for this procedure including the use ofadenoviral vectors (Mitani et al., Hum. Gene Ther. 5:941-948, 1994),adeno-associated viral (AAV) vectors (Goodman et al., Blood84:1492-1500, 1994), lentiviral vectors (Naldini et al., Science272:263-267, 1996), pseudotyped retroviral vectors (Agrawal et al.,Exper. Hematol. 24:738-747, 1996), and any other vector system now knownor later identified. Physical transduction techniques can also be used,such as liposome delivery and receptor-mediated and other endocytosismechanisms (see, for example, Schwartzenberger et al., Blood 87:472-478,1996). This invention can be used in conjunction with any of these orother commonly used nucleic acid transfer methods. Appropriate means fortransfection, including viral vectors, chemical transfectants, orphysico-mechanical methods such as electroporation and direct diffusionof DNA, are described by, for example, Wolff et al., Science247:1465-1468, (1990); and Wolff., Nature 352:815-818, (1991).

It is further contemplated that the present invention provides a kitcomprising the compositions of this invention. It would be wellunderstood by one of ordinary skill in the art that the kit of thisinvention can comprise one or more containers and/or receptacles to holdthe reagents (e.g., drugs, antibodies, small molecules, nucleic acid,etc.) of the kit, along with appropriate buffers and/or diluents and/orother solutions and directions for using the kit, as would be well knownin the art. Such kits can further comprise adjuvants and/or otherimmunostimulatory or immunomodulating agents, as are well known in theart.

The compositions and kits of the present invention can also includeother medicinal agents, pharmaceutical agents, carriers, diluents,immunostimulatory cytokines, etc. Actual methods of preparing suchdosage forms are known, or will be apparent, to those skilled in thisart.

The efficacy of treating or preventing Chlamydia infection by themethods of the present invention can be determined by detecting aclinical improvement as indicated by the absence of symptoms or otherclinical indicators of infection and/or by a change in the subject'ssymptoms and/or clinical parameters, as would be well known to one ofskill in the art.

The following examples are included to demonstrate various embodimentsof the invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples that follow representtechniques discovered by the inventors to function well in the practiceof the invention. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments that are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention.

EXAMPLES Example 1 Activation of Epidermal Growth Factor (EGFR) isRequired for Chlamydia trachomatis Development

Chlamydia trachomatis (C. trachomatis) is a clinically significant humanpathogen and one of the leading causative agents of sexually transmitteddiseases. As obligate intracellular bacteria, C. trachomatis has evolvedstrategies to redirect the host's signaling and resources for its ownsurvival and propagation. Despite the clinical notoriety of Chlamydiainfections, the molecular interactions between C. trachomatis and itshost cell proteins remain elusive. In this study, we focused on theinvolvement of the host cell epidermal growth factor receptor (EGFR) inC. trachomatis attachment and development. A combination of molecularapproaches, pharmacological agents and cell lines were used todemonstrate distinct functional requirements of EGFR in C. trachomatisinfection. We show that C. trachomatis increases the phosphorylation ofEGFR and of its downstream effectors PLCγ1, Akt and STAT5. While bothEGFR and platelet-derived growth factor receptor-β (PDGFRβ) arepartially involved in bacterial attachment to the host cell surface, itis only the knockdown of EGFR and not PDGFRβ that affects the formationof C. trachomatis inclusions in the host cells. Inhibition of EGFRresults in small immature inclusions, and prevents C.trachomatis-induced intracellular calcium mobilization and the assemblyof the characteristic F-actin ring at the inclusion periphery. By usingcomplementary approaches, we demonstrate that the coordinated regulationof both calcium mobilization and F-actin assembly by EGFR are necessaryfor maturation of chlamydial inclusion within the host cells. Aparticularly important finding of this study is the co-localization ofEGFR with the F-actin at the periphery of C. trachomatis inclusion whereit may function to nucleate the assembly of signaling protein complexesfor cytoskeletal remodeling required for C. trachomatis development.Cumulatively, the data reported here connect the function of EGFR to C.trachomatis attachment and development in the host cells, leading to newvenues for targeting C. trachomatis infections and associated diseases.

C. trachomatis is one of the leading causative agents of sexuallytransmitted diseases. As an intracellular pathogen it has evolvedstrategies to redirect hosts' signaling and resources for its ownsurvival and propagation. The recruitment of tyrosine phosphorylatedproteins at the site of entry in the host cell and the requirement ofactin polymerization along the time course of infection are welldocumented. However, a function of receptor tyrosine kinases beyond thestages of attachment and entry in the host cell has never been reported.The studies presented here show that expression and phosphorylation ofhost cell epidermal growth factor receptor (EGFR) is required for C.trachomatis development. Most importantly, C. trachomatis can regulatethe phosphorylation and intracellular localization of EGFR.Co-localization of EGFR with the F-actin at the periphery of C.trachomatis inclusion in the host cells is a particularly exciting andnovel finding implicating EGFR in the regulation of actin polymerizationaround C. trachomatis inclusions. These studies open the opportunity toinvestigate key structural and functional elements in EGFR that arenecessary for C. trachomatis development, leading to new therapies toadvance the treatment of C. trachomatis infections and associateddiseases.

Chlamydia trachomatis (C. trachomatis) is among the most common sexuallytransmitted pathogens in the US and contributes to many conditions, suchas pelvic inflammatory disease, infertility, and others. C. trachomatishas a small genome, ˜1.0 Mb, and like viruses (e.g., HPV), depends onthe host cell for survival. The chlamydial life cycle exhibits two formsthat are relevant to chlamydial pathology. The elementary body (EB) is a‘spore-like’ infectious form, previously perceived as metabolicallyinert but recently shown to display maintenance level of metabolicactivity. Following internalization into the host cells, EBs initiatethe inclusion formation and transform into metabolically activereticulate bodies (RBs), which then replicate within the inclusion.During the time course of RB replication, the early inclusions expandand fuse to form the early-mid inclusion, which then further expandsinto the mid-late inclusion. At this stage the RBs are converted backinto EBs and are then released from the host cells through extrusion orcell lysis. The process of C. trachomatis development fromattachment/entry to extrusion/exit, is regulated by an arsenal of C.trachomatis and host cell proteins. For example, several groups reportedthe recruitment of tyrosine-phosphorylated host cell proteins at thesite of C. trachomatis entry into the host cell and the requirement ofactin polymerization along the time course of infection. In accordancewith this, previous studies have shown that Chlamydia muridarum (C.muridarum), a species closely related to C. trachomatis, inducesactivation of two host cell surface receptor tyrosine kinases: thefibroblast growth factor receptor (FGFR), and the platelet derivedgrowth factor receptor β (PDGFRβ). FGFR and PDGFRβ have been proposed tobe important for binding of the chlamydial EBs to the host cell. PDGFRβis phosphorylated upon C. muridarum infection and can function as areceptor for bacterial binding to the host cell. A function for PDGFRactivation beyond this stage was not reported. C. muridarum alsorecruits FGF2 signaling to enhance infection and bacterial spread. Inthis case, FGF2 acts as a bridging molecule between the EBs and thereceptor that results in the activation of FGFR and bacterial uptake inthe host cells.

In the present study, evidence is provided that identifies EGFRsignaling as the first host cell receptor pathway required for C.trachomatis development within the host cell. Our data show: a) distinctfunctional requirements of EGFR versus PDGFR during C. trachomatisinfection—we demonstrate that PDGFR is critical only at the step ofbacterial attachment, and that knockdown of EGFR but not PDGFR impairsdevelopment of C. trachomatis inclusions within the host cell; b)infection with C. trachomatis increases phosphorylation of EGFR and ofits downstream effectors PLCγ1, Akt and STAT5; c) C. trachomatisinfection results in re-localization of EGFR at the periphery of C.trachomatis inclusion inside the host cell; and d) inhibition of EGFRresults in the formation of a diffuse assembly of F-actin at theperiphery of incompletely developed inclusions. Co-localization of EGFRwith the F-actin at the periphery of C. trachomatis inclusion is aparticularly exciting and novel finding implicating EGFR in theregulation of actin polymerization around C. trachomatis inclusions.

C. trachomatis Induces EGFR Phosphorylation and Activation of EGFRSignaling Pathways.

To assess the role of EGFR in C. trachomatis development, we initiatedour studies by comparing the chlamydial inclusion formation betweenisogenic cell lines, MEFs EGFR^(+/+) (mouse embryonic fibroblasts) andEGFR null MEFs (MEFs EGFR^(−/−)). Both cell lines were infected withchlamydial EBs and at 24 hours post infection (hpi) the cells werestained with chlamydial FITC-conjugated anti-lipopolysaccharide (LPS)mAb as described herein. Confocal imaging was performed to visualize thedevelopment of chlamydial inclusions. Well-developed C. trachomatisinclusions were observed in MEFs EGFR^(+/+) while in the MEFs EGFR^(−/−)cells, the inclusions were significantly smaller in size in comparisonto MEFs EGFR^(+/+) (FIG. 1A, quantification is shown in FIG. 4B). Theseinitial results indicated a role of EGFR in C. trachomatis infection andprompted us to explore it further. We first examined whether C.trachomatis could induce EGFR phosphorylation in infected cells. Toensure the results were not biased by the selection of cell line, bothHeLa cells and MEFs EGFR^(+/+) were used in these experiments. The MEFsEGFR^(+/+) cells were infected with chlamydial EBs and lysed atdifferent time points ranging from 0.5 hpi to 5 hpi. We observed asignificant 1.8-fold increase in phosphorylation of Y1173 in EGFR thatpeaked at 2.5 hpi (P<0.05) (FIGS. 1B-C). Similar results were obtainedin HeLa cells (FIGS. 1D-E), in which we also observed an increase inPDGFRβ phosphorylation (FIG. 1F). We further analyzed thephosphorylation of EGFR at other tyrosine residues (Y845, Y992, Y1045and Y1148). An increased phosphorylation was observed in C.trachomatis-infected MEFs EGFR^(+/+) (2.5 and 5 hpi) at all sitesanalyzed with the exception of Y1148 (FIG. 1G). The results show that C.trachomatis can enhance EGFR activity and indicates a function of EGFRsignaling in C. trachomatis infection.

EGFR activation in response to extracellular cues (e.g., EGF ligand) isknown to activate PI3K/Akt, PLCγ1 (phospholipase Cyl 1) and STATproteins (signal transducers and activators of transcription). Todetermine whether C. trachomatis-induced EGFR phosphorylation can alsoactivate its downstream effector proteins, the phosphorylation of PLCγ1(Y783), Akt (S473) and STAT5 (Y694) was monitored in MEFs EGFR^(+/+) andEGFR^(−/−) cells infected with chlamydial EBs at time points rangingfrom 2.5 hpi to 18 hpi. As shown in FIG. 2A and the quantification inFIG. 2B, C. trachomatis infection induced a significant increase inphosphorylation of EGFR and its downstream targets, PLCγ1, Akt and STAT5at 2.5, 5 and 10 hpi (P<0.05). At 18 hpi, the phosphorylation of EGFR,Akt and PLCγ1 returned close to the basal level. The phosphorylation ofSTAT5 persisted at 18 hpi, presumably due to delayed kinetics orsecondary activation subsequent to primary stimulus. The EGFR dependenceof these phosphorylation events was further confirmed by the experimentsin MEFs EGFR^(−/−) cells. Under these conditions, C. trachomatisinfection at the same time points did not induce an increase inphosphorylation of PLCγ1, Akt and STAT5 proteins (FIG. 2C). Combinedwith our previous observation of phenotypically smaller inclusionsformed in MEFs EGFR^(−/−) cells (FIG. 1A), these findings led us tohypothesize that activation of an EGFR-dependent signaling axis wasessential for establishing a successful C. trachomatis infection. Tofurther confirm that the activation of these proteins was C.trachomatis- and EGFR-dependent, we investigated the C.trachomatis-induced activation of PLCγ1, STAT5 and Akt in MEF EGFR^(+/+)and HeLa cells using multiple methods of EGFR inhibition. MEFsEGFR^(+/+) cells were treated with EGFR siRNA for 48 h, then infectedwith C. trachomatis for 2.5 h and tested for activation ofPLCγ1, STAT5and Akt. Chlamydial infection resulted in increased phosphorylation ofall three proteins in cells treated with control siRNA but not in cellstreated with EGFR siRNA (FIGS. 3A-B; P<0.01). C. trachomatis-inducedphosphorylation of EGFR, PLCγ1, STAT5 and Akt was also inhibited bytreatment of HeLa and MEFs EGFR^(+/+) with Cetuximab, a monoclonalantibody that binds to the extracellular domain of EGFR and specificallyblocks EGFR functions (FIGS. 3C-E). These studies confirmed EGFRactivation as one of the upstream regulatory events in thephosphorylation of PLCγ1, STAT5 and Akt signaling in C.trachomatis-infected cells.

EGFR is Essential for the Formation of Mature Chlamydial Inclusions.

Next, we assessed the contribution of EGFR to the formation of C.trachomatis inclusions in HeLa cells and MEFs. EGFR was inhibited byusing Erlotinib, Cetuximab or EGFR siRNA. Erlotinib is a small moleculeinhibitor that targets the intracellular kinase domain of EGFR, whileCetuximab blocks the binding of EGF to its cognate receptor and thusblocks receptor activation. Effective inhibition of EGFR phosphorylationby Erlotinib or Cetuximab was confirmed by Western blot (FIGS. 10, 11and 3C). Similarly, Western blot analysis was performed to confirm thedepletion of EGFR protein in HeLa and MEFs treated with EGFR siRNA(FIGS. 12 and 3A). HeLa cells with or without EGFR inhibition (proteindepletion or inhibition of function), were infected with C. trachomatis.The cells were immunostained using anti-chlamydial LPS mAb at 24 hpi andanalyzed by confocal imaging to quantify the size and number ofinclusions. In comparison to control (DMSO, IgG or control siRNA treatedcells), there was a significant decrease in both the number and size ofchlamydial inclusions under all treatment conditions (P<0.01 to P<0.001;FIG. 4A). Use of multiple approaches to inhibit EGFR discounts thepossibility of observing these results because of an unspecificinteraction of the inhibitors with non-target molecules, a potentialcaveat of using pharmacological agents. The decreased chlamydialinfection upon EGFR inhibition was further confirmed by monitoring thechlamydial Hsp60 using Western blot analysis (FIG. 13). To ensure thatErlotinib and Cetuximab treatments did not affect the viability ofchlamydial EBs, we infected HeLa cells with EBs that were pretreatedwith Erlotinib or Cetuximab. At 24 hpi the cells were lysed and blottedusing antibodies against chlamydial Hsp60. The Hsp60 antigen load in thecells infected with drug-treated EBs was comparable to the infection bythe untreated EBs (FIG. 14), confirming that EGFR inhibitors did notaffect the viability of EBs in these experiments. Additional studieswere performed to ensure that the poor inclusion development was not dueto loss of the host cells' viability during Erlotinib treatment. Thehighest concentration (25 μM) and maximum duration (24 h) of Erlotinibtreatment did not reduce the viability of HeLa cells (FIG. 15).

Because we observed PDGFRβ phosphorylation triggered by C. trachomatisinfection (FIG. 1F) and the role of PDGFRβ has been established in C.muridarum attachment to host cells, we also investigated the formationof chlamydial inclusions in cells treated with PDGFRβ siRNA. Thedepletion of PDGFRβ in HeLa cells treated with PDGFRβ siRNA wasconfirmed by Western blot (FIG. 16). Similar to EGFR, depletion ofPDGFRβ decreased the number of inclusions in host cells (P<0.01);however, unlike EGFR, the size of the inclusions was not significantlyaffected by PDGFRβ siRNA treatment (FIGS. 4A and 22). These results werefurther substantiated by experiments in MEFs EGFR^(−/−) cells, whichshowed similar results to the EGFR-inhibited HeLa cells (FIGS. 4B and17). We then examined the possible role of EGFR in the bacterialattachment to the cell surface and its subsequent internalization,during the early stage of C. trachomatis infection. The PDGFRβ siRNAtreated HeLa cells were included as control in these experiments. HeLacells with or without EGFR and PDGFRβ inhibition were infected with C.trachomatis for 2.5 h and processed for inside-out staining todifferentially quantify external and internalized bacteria. At 2.5 hpi asignificant decrease in cell-associated bacteria (external and internal)was observed (P<0.05 to P<0.001) in both EGFR and PDGFRβ inhibited cells(FIGS. 4C-D). Since more than 80% of the cell-associated bacteria weresuccessfully internalized into the host cell (FIGS. 4C-D), these resultspoint to defects in bacterial attachment to the host cell as a maincause for the decrease in overall chlamydial internalization. Theresults were further confirmed by Western blot analysis of chlamydialHsp60 (P<0.001; FIGS. 4E-F).

The small inclusions formed upon inhibition of EGFR were examined indetail by transmission electron microscopy experiments. Large inclusionswere observed in HeLa cells infected with C. trachomatis whereas theErlotinib and Cetuximab treated HeLa cells contained small inclusions(FIGS. 4G-H).

To further distinguish between the role of EGFR in bacterial attachmentfrom the growth-associated consequences during C. trachomatis infection,experiments were performed in which EGFR inhibitor (Erlotinib) was addedat different time points (2.5, 5 and 18 hpi), post bacterial infection.Under all conditions the total time of infection with C. trachomatis was24 h. EGFR inhibition after 2.5 and 5 hpi, impaired regular inclusionformation and resulted in formation of numerous bacterial aggregates(FIGS. 5B and C, respectively). On the other hand, EGFR inhibition at 18hpi did not significantly affect the inclusion development (FIG. 5D).These observations correlate well with the pattern of EGFR signalingshown in FIGS. 2A-B. The results were further confirmed by Western blotanalysis of chlamydial Hsp60. Significantly lower expression of Hsp60was noted in cells treated with Erlotinib at 2.5 hpi compared withErlotinib addition at 18 hpi (cells harvested at 24 hpi; FIG. 18).Together, the results described above show that EGFR has discretefunctions both at the level of bacterial attachment/internalization andsubsequent inclusion development.

EGFR Regulates Intracellular Calcium During C. trachomatis Infection.

We next tested whether EGFR could be involved in C. trachomatis-inducedcalcium release in host cells. HeLa cells were treated with controlsiRNA, EGFR siRNA or PDGFRβ siRNA followed by C. trachomatis infection.At 2.5 and 5 hpi cells were analyzed by fluorescence microscopy forintracellular calcium. At 2.5 and 5 hpi, a significant increase incalcium was observed upon C. trachomatis infection in control siRNA andPDGFRβ siRNA treated cells but not in EGFR siRNA treated cells (FIGS.6A-B; P<0.001). In another set of experiments, Erlotinib was added at2.5 and 5 hpi and cells were incubated for up to 24 hpi when they werestained for calcium. A significant drop in calcium signal was observedin C. trachomatis-infected cells that had been treated with Erlotinib at2.5 and 5 hpi (FIG. 19). Examination of these results, in combinationwith the observations described in FIG. 5 suggests that EGFR-inducedcalcium release is necessary for the development of C. trachomatisinclusions. Next, we mimicked a calcium deficient environment bytreating HeLa cells with the calcium chelator BAPTA/AM for 1 h followedby C. trachomatis infection for 24 h. A significant decrease in bothinclusion size and number was noted, similar to the conditions of EGFRinhibition in HeLa cells (FIG. 6C). Impaired inclusion formation wasalso observed in C. trachomatis-infected cells treated with BAPTA/AM at2 and 5 hpi (more severe in 2 hpi BAPTA/AM treated cells) compared withthe control DMSO treated cells (FIG. 6D). The addition of Ionomycin (acalcium ionophore) to EGFR siRNA treated cells was not able to rescuethe formation of chlamydial inclusion (FIG. 20). This shows that acoordinated and synchronized regulation of EGFR-dependent calciumrelease along with other factors regulated by EGFR are required forformation of inclusions within the host cells.

EGFR is Essential for F-Actin Assembly Around Chlamydial Inclusions.

To examine the role of EGFR in arrangement of F-actin at the inclusionperiphery, HeLa cells treated with Erlotinib, Cetuximab, and EGFR siRNAwere infected with C. trachomatis for 24 h and processed for confocalmicroscopy to visualize the intracellular arrangement of F-actin. Weobserved formation of a distinct F-actin ring at the inclusion peripheryin C. trachomatis infected control cells (DMSO, control siRNA or IgGcontrol) (FIGS. 7A, 7D). In the EGFR siRNA treated cells, thearrangement of F-actin around the C. trachomatis inclusion was eitherdiffused or disorganized (FIG. 7B). Similar results were observed in theErlotinib and Cetuximab treated HeLa cells (FIGS. 7C-D), as well as inthe MEFs EGFR^(−/−) cells (FIG. 7E).

Since EGFR is an F-actin binding protein, we performed additionalexperiments to investigate whether EGFR co-localizes with F-actin ringat the periphery of inclusion. HeLa cells were infected with C.trachomatis and at 24 hpi the cells were stained for C. trachomatis EB,EGFR and F-actin (FIG. 8A). Co-localization of EGFR and F-actin at theperiphery of C. trachomatis inclusion was evidenced by overlappingfluorescence signals (FIG. 8A, Merge). The normalized mean deviationproduct (nMDP) was calculated for each pixel in the image to identifyregions of intense co-localization or exclusion within the image. Theresulting nMDP color maps of the whole cell and the inclusion area(dashed box in FIG. 8A) show areas with co-localization ranging frommoderate to intense, with no areas of exclusion (FIG. 8B). The intensityprofile for a cross-section in FIG. 8A, which includes from top left tobottom right (left to right in the intensity profile plot), shows clearenrichment of EGFR and F-actin at the periphery of inclusion as well asthe cell membrane (FIG. 8C). Quantitative processing of the image datashown in FIG. 8 was performed using a number of independent algorithms,which are described in the legend for FIGS. 23-29. Similar analysis wasapplied to other 7 inclusion areas and 8 non-inclusion areas (cells thatwere not infected with C. trachomatis) and all five parameters showsignificant increase of EGFR and F-actin co-localization in inclusionareas compared with non-inclusion areas (p<0.001, FIG. 8D). Additionalrepresentative images and analyses are shown in FIGS. 24-29.Collectively, all quantitative analyses show strong and statisticallysignificant evidence of co-localization of EGFR and F-actin at theperiphery of inclusion.

As an intracellular pathogen, C. trachomatis has developed an arsenal ofmolecular tools that enables it to hijack signaling and metabolicpathways of the host cell and establish an intracellular niche favorableto its development. An extensive network of interactions exists betweenC. trachomatis and host proteins to facilitate bacterial attachment andentry and C. trachomatis development in the host cell. C. trachomatiscan interact with and modulate the activity of numerous cell surfacereceptors to promote attachment and entry into the host cell. EGFR is animportant cell surface receptor tyrosine kinase with a central role incell growth, proliferation and migration. We provide here the firstevidence that C. trachomatis has the ability to upregulate EGFR activityin host cells and establish EGFR as a critical effector molecule in theformation of chlamydial inclusions within the host cells.

We demonstrate that C. trachomatis induces an increase in EGFRphosphorylation and that inhibition of EGFR phosphorylation or depletionof EGFR protein impairs C. trachomatis attachment and its development inthe host cells. Our results are further supported by the EGFR-dependentincrease in phosphorylation of downstream targets like Akt, STAT5 andPLCγ1 in C. trachomatis infected cells. The lack of Akt phosphorylationin EGFR^(−/−) cells demonstrates EGFR as the upstream regulator of Aktphosphorylation, which was not known before.

We demonstrate here that inhibition of EGFR abrogates the C.trachomatis-induced increase in intracellular calcium flux. Also,removal of calcium by chelation resulted in marked reduction in the sizeand number of chlamydial inclusion similar to EGFR inhibition.

Our data show distinct co-localization of EGFR with the F-actin ringaround the chlamydial inclusion and interruption in the formation ofF-actin rings around the chlamydial inclusions in both calcium depletedand EGFR inhibited cells.

EGFR-dependent regulation of F-actin and calcium release can affectinclusion formation at multiple stages of C. trachomatis infection.First, it can have a direct effect on the bacterial attachment andentry. Consistent with this, our data indicate that EGFR inhibitionsignificantly impairs the bacterial attachment to the host cell surfaceat a level comparable with inhibition of PDGFRβ

In summary, the studies included here show that chlamydial infectionupregulates EGFR activity in host cells. This results in activation ofdownstream effectors of EGFR such as PLCγ1, Akt and STAT5. Wedemonstrate that EGFR and EGFR-mediated signaling play a role in both C.trachomatis attachment and development of C. trachomatis inclusions inhost cells through mechanisms that involve EGFR-dependent regulation ofcalcium release, actin cytoskeleton rearrangement, and EGFRco-localization with F-actin at the inclusion periphery. These findingsshed light on the complexity of C. trachomatis-host cell interactions,which open new venues to treat C. trachomatis infections and C.trachomatis-associated diseases. These results form the basis of themodel we propose in FIG. 9. In this model, EGFR plays a key role in theearly and middle stages of C. trachomatis infection wherein the EGFRmediated calcium signaling and F-actin remodeling are central to theestablishment of a successful C. trachomatis infection inside theeukaryotic cells.

Reagents.

Antibodies were obtained from the following sources: goatanti-chlamydial LPS, goat anti-C. trachomatis EB (Meridian LifeSciences, Saco, Me., USA); FITC conjugated anti-chlamydial EBs(Fitzgerald, Mass., USA), rabbit anti-EGFR, rabbit anti-PLCγ1, rabbitanti-pPLCγ11, rabbit anti-StatS, rabbit anti-pStatS, rabbit anti-Akt,rabbit anti-pAkt, rabbit anti-pPDGFRβ (Y751), rabbit anti-EGFR (AlexaFluor 594 conjugate) and rabbit anti-β actin (Cell Signaling, Danvers,Mass., USA); rabbit anti-pEGFR (Y1173), rabbit anti-PDGFRβ, mouseanti-chlamydial Hsp60 and rabbit anti-mouse IgG HRP antibodies (SantaCruz Biotechnology, Santa Cruz, Calif., USA); rabbit anti-pEGFRantibodies (Y845, Y992, Y1045, Y1148; Millipore, Temecula, Calif., USA);donkey anti-goat IgG H&L (Alexa Fluor 405) (Abcam, Cambridge, Mass.,USA); anti-EGFR-Alexa Fluor 488 antibody (Millipore, Temecula, Calif.,USA), goat anti-rabbit IgG HRP, FITC-conjugated anti-rabbit antibody andrhodamine red conjugated anti-goat secondary antibodies (JacksonLaboratories, West Grove, Pa., USA). EGFR siRNA (human and mouse),PDGFRβ siRNA (human), control siRNA and siRNA transfection reagents wereobtained from Santa Cruz Biotechnology, Santa Cruz, Calif., USA andDharmacon USA. DMEM, DMEM (Ca⁺⁺ free), FCS, FBS and Alexa Fluor 488phalloidin and Fluo-4 AM were purchased from Invitrogen, Grand Island,N.Y., USA. Pathfinder Chlamydia Culture Confirmation System waspurchased from BioRad, Hercules, Calif., USA. HBSS and PBS werepurchased from Lonza, Walkersville, Md., USA. DEAE dextran, BAPTA/AM,lonomycin, and cyclohexamide were purchased from Sigma Aldrich, St.Louis, Mo., USA. Cell Proliferation Kit I (MTT) and Fast Start UniversalSYBR green (Rox) were obtained from Roche, Indianapolis, Ind., USA.Erlotinib was purchased from Selleck Chemicals LLC, Houston, Tex., USAand Cetuximab was obtained from Yale University. Bicinchoninic acid(BCA) assay for protein quantification was purchased from ThermoScientific, Rockford, Ill., USA. ECL Plus Western blotting detectionreagent was purchased from Perkin Elmer, Waltham, Mass., USA.

Cell Culture.

Chlamydia trachomatis strain D, HeLa and NIH 3T3 were purchased fromATCC. Mouse embryonic fibroblasts (MEFs EGFR^(+/+) and EGFR^(−/−)) wereobtained from the University of Pittsburgh. HeLa and MEFs were culturedusing DMEM+10% FBS. NIH 3T3 cells were cultured in DMEM+10% FCS. Allcell lines were maintained at 37° C. and 5% CO₂.

Propagation of Chlamydia and Infections.

Chlamydia trachomatis strain D (C. trachomatis) was propagated in HeLacells grown in complete DMEM containing cyclohexamide (2 μg/ml). After48 h, infected cells were harvested in sucrose-phosphate-glutamate (SPG)buffer, ruptured by vortexing with 3 mm glass beads. EBs were purifiedusing previously described methods. The resulting bacterial pellet wasresuspended in cold SPG buffer with a 21 to 22-gauge injection needleand stored in aliquots at −80° C. For infection, chlamydial EBs wereadded to cells in monolayer (80% confluence) at a multiplicity ofinfection (MOI) of 2-10 for all studies included here. Centrifugationwas not used during the infection.

Immunoblotting.

Cells were harvested and lysed in modified RIPA buffer (50 mM Tris, 150mM NaCl, 1% sodium deoxycholate, 1% NP-40, 1 mM sodium fluoride)supplemented with protease inhibitor cocktail and phosphatase inhibitortablet (Roche). For Western blotting of C. trachomatis antigens, the C.trachomatis-infected cells were lysed in 20 mM HEPES buffer (pH 8.0)containing 8 M urea supplemented with protease inhibitors. Cell lysateswere incubated on ice for 1 h and then sonicated briefly. The solubleprotein fraction was collected by centrifugation at 10,000 rpm. Totalprotein was estimated using the BCA method and equal amounts of proteins(10-20 μg) were processed for immunoblotting. Proteins were resolved on10% SDS polyacrylamide gel and transferred onto a nitrocellulosemembrane. The blot was blocked using 3% BSA and incubated with theindicated antibodies. ECL was used to detect the proteins according tothe manufacturer's instructions.

siRNA Transfections.

Cells were grown to 60% confluency followed by transfection with EGFRsiRNA/PDGFRβ siRNA or control siRNA (Santa Cruz/Dharmacon) according tomanufacturer's protocol. After 24 h, transfected cells were replated fora second round of transfection. After another 24 h, cells were infectedwith C. trachomatis and incubated for different time intervals (siRNAwas maintained during the infection) according to the experimentaldesign and were either stained for analyzing the inclusion developmentor prepared for Western blot analysis.

EGFR Inhibitor Treatment.

Erlotinib and Cetuximab treatments were used for EGFR inhibition. Thecells were pretreated with Erlotinib (25 μM) for 2 h and then infectedwith C. trachomatis. For Cetuximab treatment, cells were treated with 20μg/ml drug for 2 h in DMEM +0.1% FBS followed by C. trachomatisinfection. The inhibitor concentration was maintained during theinfection. In certain experiments in which protein phosphorylation wasinvestigated (FIGS. 1B, 1D, IF, 1G, 2, 3 and 11) the cells were serumstarved overnight before drug treatment and C. trachomatis infection.DMSO was used as the vehicle control for Erlotinib and IgG was used ascontrol treatment for Cetuximab. Infected samples were used either forWestern blotting or confocal imaging as described below. In another setof experiments the cells were infected with C. trachomatis followed byaddition of Erlotinib at 2.5, 5 and 18 hpi. The total time for C.trachomatis infection was 24 h after which the samples were used forWestern blotting or confocal imaging.

Control Experiments.

Chlamydial EBs were mixed with complete DMEM (DMEM+10% FBS) containingeither 25 μM Erlotinib, 20 μg/ml Cetuximab or DMSO and incubated for 2.5h at 37° C., and centrifuged at 16,000 rpm at 4° C. for 30 minutes. EBpellets were washed and resuspended in SPG buffer and used forsubsequent HeLa cell infection. At 24 hpi cells were lysed for Westernblotting of chlamydial Hsp60 antigen.

Inside Out Staining.

Differential staining of external and internalized bacteria wasperformed as described previously and using three independent studies.Briefly, cells were grown overnight in 2-well Lab-Tek chamber slides andtreated with either EGFR inhibitors or siRNA as described above andsubsequently infected with Chlamydia for 2.5 h at 37° C. to allow forbacterial attachment and internalization. For blocking EGFR withCetuximab, cells were preincubated with Cetuximab or control IgG for 2 hbefore addition of bacteria. Infected cells were washed five times inPBS and fixed in 1% paraformaldehyde (PFA). After fixation, cells wereblocked in 5% BSA for 1 h and then incubated with FITC-conjugatedantibody against chlamydial EBs for 1 h to stain external EBs. Cellswere then permeabilized with 0.1% Triton X-100, blocked again, andincubated with antibody against chlamydial LPS followed by incubationwith rhodamine-conjugated anti-goat antibody to stain intracellular andextracellular EBs. Imaging was performed using confocal microscopy (CarlZeiss, Germany). The quantification for the inside out experiments wasperformed manually based on the number of attached EBs observed perinfected cell. The statistical analysis was based on imaging datacollected from fifteen fields containing 3-10 cells per field asdescribed below.

Immunofluorescence.

Cells were infected with C. trachomatis as described above. The cellswere washed 5 times with PBS and fixed at either 2.5 hpi or 24 hpi with4% PFA for 10 min and blocked with 5% BSA for 1 h. After washing withTBS (50 mM Tris HCl, pH 7.4 and 150 mM NaCl) the cells werepermeabilized for 15 min with 0.1% Triton X-100 and again washed withTBS followed by incubation with the indicated primary antibodiesovernight. The cells were washed three times (10 min each) with TBS andincubated with appropriate secondary antibodies and Alexa Fluor488-phalloidin (1:40 dilution in PBS) for 1 h. After repeated washings,the coverslips were mounted and analyzed using Zeiss LSM 510 or 710laser scanning confocal microscope. For the studies shown in FIG. 1A, C.trachomatis inclusions were stained using the Pathfinder ChlamydiaCulture Confirmation System (BioRad, Hercules, Calif., USA). At 24 hpost C. trachomatis infection, cells were fixed with methanol for 10 minat room temperature and stained with the FITC conjugated pathfinderanti-chlamydial mAb according to the manufacturer's protocol (Bio-Rad,Hercules, Calif.). For the co-localization studies, 30,000 HeLa cellswere seeded into EZ slide 4-well glass slides (Millipore, Temecula,Calif., USA) and infected with C. trachomatis as described above for 2.5h the next day. Cells were fixed 24 h later in 4% formaldehyde in PBSfor 15 min, permeabilized in 0.1% Triton X-100 for 10 min, and blockedin 1% BSA for 1 h at room temperature. Then the cells were incubatedwith anti-EGFR rabbit mAb (Alexa Fluor 594 conjugate, Cell Signaling,Danvers, Mass., USA) overnight at 4° C., followed by incubation withAlexa Fluor 488 Phalloidin (Invitrogen, Grand Island, N.Y., USA) for 1 hat room temperature. The slides were mounted with Fluoromount mountingmedium (Sigma Aldrich, St. Louis, Mo., USA), sealed, and examined usingZeiss 710 laser scanning confocal microscope.

Intracellular Calcium Staining.

Cells were washed with calcium free incomplete DMEM and incubated with 2μM Fluo-4 AM diluted in Ca²⁺⁺ free incomplete DMEM at 37° C. for 30 min.The cells were then washed with Ca²⁺⁺ free HBSS and analyzed for calciumlevels using an Olympus IX71 fluorescence microscope.

BAPTA/AM and Ionomycin Treatment.

Monolayers of HeLa cells were washed with PBS and replaced with calciumfree DMEM+1% FBS and pretreated for 1 h with BAPTA/AM (15 M) followed byC. trachomatis infection for 24 h. BAPTA/AM concentration was maintainedduring the C. trachomatis infection. The control cells were treated withDMSO (<0.1%) followed by 24 h of C. trachomatis infection. In anotherset of experiments, HeLa cells were infected with C. trachomatisfollowed by addition of BAPTA/AM (15 μM) or DMSO at 2 or 5 hpi. Thetotal time for C. trachomatis infection was 24 h. To induce mobilizationof calcium from intracellular stores to the cytoplasm, cultured cellswere pretreated for 1 h with 1 μg/ml Ionomycin before chlamydialinfection. C. trachomatis-infected cells were washed three times withPBS after 24 hpi and processed for immunofluorescence as describedabove.

Cell Proliferation Assay.

To ensure that the dose of Erlotinib (25 μM) provided maximal inhibitionwithout affecting cell viability, MTT assays were performed. HeLa cellswere cultured for 24 h, treated with 25 μM Erlotinib and incubated at37° C., 5% CO₂ for 24 h. After washing the cells, the procedure for cellviability assay was followed as per manufacturer's instructions (Roche).

Transmission Electron Microscopy.

HeLa cells were infected with C. trachomatis as described above.Twenty-four hours post chlamydial infection the cells were washed withPBS and fixed with 2.5% glutaraldehyde in 0.1 N Millonig's buffer (pH7.2) for 1 h at room temperature. The cells were then washed andpost-fixed for 1 h in 1% osmic acid in 0.1 N Millonig's buffer followedby 1 h treatment with 1% uranyl acetate. A graded ethanol series (25%,50%, 70-75%, 90-95% and 100%) was used to dehydrate the cells prior toembedding in Spurr's resin. Thin sections were then cut with a Reichertultracut E microtome and stained with 1% uranyl acetate and Reynold'slead citrate solutions, followed by the analysis using 80 kV TecnaiSpirit BioTwin transmission electron microscope.

Image Acquisition and Statistical Analysis.

Images of stained cells were acquired in a Z-series on a Zeiss LSM 710AxioObserver Z.1 inverted laser scanning confocal microscope using aZeiss Plan-Apochromat 63×/1.3 water-immersion objective with 3× digitalzoom at the Wake Forest University Microscopic Imaging Core Facility andConfocal Microscopy Center. Lasers of 405 nm (25 mW diode), 488 nm (35mW Argon laser), and 594 nm (2 mW He/Ne laser) were used to illuminatethe samples and images were captured using a R6357 photomultiplier tube(Hamamatsu Photonics, Hamamatsu City, Japan) with a pixel dwell time of0.79 μs. Final image magnification at the time of image capture was1,890×, with each voxel representing 0.02 μm×0.02 μm×0.39 μm. A pinholeof 53.88 μm (˜1 Airy unit for the red channel) was used for all colorchannels of all images. All images were captured at 2048×2048 pixels,saved in 8-bit .lsm image format, and converted to .tif format foranalysis in the MacBiophotonics ImageJ package (McMaster UniversityBiophotonics Facility, Hamilton, Ontario, Calif.). A median filter of7×7 pixels was applied to EGFR images using Zeiss Zen 2011 Blue Edition(Carl Zeiss Microscopy GmbH, Gottingen, Germany) to reduce backgroundnoise. Co-localization of each image was determined using eightindependent techniques. Standard overlays and intensity profile datawere generated using Zen 2011, while six different co-localizationanalysis algorithms were performed using the JACoP and ColocalizationColormap plugins for ImageJ (National Institutes of Health, USA).

ImageJ was used for quantification of the Western blots, counting andestimation of chlamydial inclusion size and for the counting of thebound and internalized EBs (inside out studies). To define thechlamydial inclusion number and size, at least fifteen random fieldswere analyzed for each result. The number of inclusions was calculatedper 10⁵ cells and expressed as a percentage of the respective controls.Similarly, fifteen random fields (3-10 cells per field) were used forthe inside out experiments. All results are presented as mean±SEM. At-test was used for comparisons and calculating the level ofsignificance using SigmaPlot version 12.0.

Example 2 Identification of Cancer Relevant Biomarkers of InfectionUsing Western Blot (WB) and Quantitative Mass Spectrometry (MS)

We initiated a series of targeted and discovery screening experiments toevaluate changes in protein, protein phosphorylation and proteinoxidation in cells infected with C. trachomatis. Targeted analysis for anumber of key signaling proteins is shown in FIG. 30. Important for thisdisclosure, the results revealed down-regulation of MKK4 at 12 and 24hpi (hours post-infection) with C. trachomatis (FIG. 30). MKK4 is animportant suppressor of metastasis. Down-regulation of MKK4 uponinfection with C. trachomatis is significant for several reasons: i) itsupports MKK4 as a potential biomarker of infection associated withunique developmental stages of C. trachomatis and cancer; ii) it opensopportunities for identifying MKK4-centered signaling networks thatcould be manipulated to prevent or combat chlamydial infections andcancer; and, iii) it could lead to the development of novel therapies tointerfere with tumor metastasis. Since MKK4 is known to activate p38 andJNK pathways, we monitored phosphorylation of p38 and JNK. p38phosphorylation decreased at 12 and 24 hpi as expected; however, JNKphosphorylation increased, suggesting compensatory mechanisms. Inaddition, C. trachomatis also induced phosphorylation of STAT3, STAT5,c-Raf and AKT. STAT3/5 can activate the Bcl-2 family of proteins, whichleads to inhibition of mitochondrial cytochrome c release anddown-regulation of apoptosis. The WB data suggest an anti-apoptotic,pro-proliferative state of C. trachomatis infected cells. STAT proteinsare known mediators of angiogenesis and therefore important for tumorgrowth.

Summary of MS Data.

Comparative Western analysis can provide insight into specific molecularfeatures of host-pathogen interactions; however, because of the limitedlinear range of detection, it is not feasible to apply this or otherantibody-based technologies to quantitative, wide-scale investigationsof global proteomic changes. Mass spectrometry (MS) has emerged as analternative technology for quantitative, high-throughput studies ofcomplex biological samples. Label-free quantitation, stable isotopedilution and stable isotope labeling with amino acids in cell culture(SILAC) are the top methods of quantification in MS studies ofbiological systems. MS has previously been applied to investigatehost-pathogen interaction in cancer (e.g., H. pylori). No such studieshave been reported for HPV or C. trachomatis.

We thus ran a series of preliminary experiments to determine the effectsof C. trachomatis infection on head and neck cancer. Proteomic changesinduced by C. trachomatis in SQ-20B (head and neck cancer cell line)were quantified using mass spectrometry and SILAC (uninfected Arg0/Lys0,infected (24 hpi) Arg10/Lys8) and data were analyzed using IngenuityPathways Analysis (Ingenuity® Systems). A total of 221 mapped IDs wereidentified as down-regulated and 195 as up-regulated by infection withC. trachomatis at 24 hpi (threshold of fold-change set at 1.5). Thecontribution of these to various molecular and cellular functions isshown in FIG. 31A. Interestingly, the top diseases these proteins mappedto were cancer and infectious diseases. Because C. trachomatis has beenreported to cause centrosomal defects, we were intrigued to find animbalance in down-regulation of proteins involved in cell cycle control.In particular, regulation of the G2/M checkpoint is important formaintaining genomic stability and preventing cells from undergoingmalignant transformation. Proteins that were down- or up-regulated by C.trachomatis were mapped to the G2/M checkpoint pathway shown in FIG.31B. Down-regulated proteins relevant to control of cell cycle were:ATR, cyclin B1, GADD45 (highlighted in FIG. 31B), and MDM1, an isoformof MDM2 (FIG. 31B). MDM1 has not yet been characterized with respect toits function in cell cycle control. MDM2's function is to sequester p53,and MDM1 could potentially have a similar role. Two proteins wereup-regulated, YWHAE and RbL1 at 24 hpi (FIG. 31B). RbL1 is relevant toregulation of the G1/S checkpoint.

To determine whether any of the C. trachomatis-regulated proteins in ourdataset have biomarker potential, the dataset was filtered using IPABiomarker filter with the following restrictions: cancer-relevant,application for diagnosis and monitoring of disease progression, andpresence in biofluids that are readily available (plasma/serum andsaliva). Nine of the proteins that were down-regulated and six of thoseup-regulated passed the cancer biomarker filter. Among these were heatshock protein 70 kDa (HSPA8), mitochondrial superoxide dismutase 2, andendothelial nitric oxide synthase 3 (all up-regulated), andalpha-fetoprotein, apolipoprotein A-1, early growth response 1,peroxiredoxin 3, and MKI67-antigen identified by monoclonal antibodyKi-67 (all down-regulated). Studies using clinical specimens are ongoingto further verify these as emerging biomarkers of Chlamydia infection.

C. trachomatis Infection Induces Reactive Oxygen Species (ROS) and thisis EGFR-Dependent.

Previous studies have shown that human cervical pre-neoplastic andneoplastic lesions are characterized by decreased catalase activityaccompanied by an increase in H₂O₂ . C. trachomatis is known to increaseROS in host cells through a mechanism dependent on NADPH oxidase, anenzyme that catalyzes the electron transfer from NADPH to molecularoxygen to produce superoxide. EGFR and a number of other receptortyrosine kinases are known activators of NADPH oxidase. We asked whetherC. trachomatis-induced ROS is dependent on EGFR. Data in FIG. 32 showthe results of experiments performed in EGFR WT and EGFR KO MEFs. Cellswere infected with Chlamydia at increasing multiplicity of infection(MOI) and the increase in ROS at 5 hpi was quantified using thefluorescent dye DCF (CM-H2DCFDA, Invitrogen) and imaging. A strongdependence of ROS on the MOI was observed in EGFR WT compared with KOcells. This confirms EGFR-dependent activation of NADPH oxidase as themajor source of ROS in infected cells.

Infection with C. trachomatis Induces Cell Transformation.

Many studies show a good correlation between in vitro celltransformation by cancer-inducing agents and tumor development in vivo.For example, HPV's potential to induce cell transformation establishedthis viral pathogen as a causative factor for cervical and head and neckcancer. The most stringent and common test for cell transformation is tomonitor anchorage-independent growth as colony formation in soft agar.We applied this method to monitor colony growth of Ct infected anduninfected NIH 3T3 cells (FIG. 33). In comparison to the control NIH 3T3cells (upper panel, left), large colonies were observed for C.trachomatis-infected NIH 3T3 cells (upper panel, right) after four weeksof incubation. We analyzed two of these clones with respect to cellcycle distribution. In comparison to the control, increased cellpopulation in G2/S phase of the cell cycle was observed in transformedNIH 3T3 clones. This is the first evidence of cell transformation by C.trachomatis alone, supporting the tumor-inducing potential of thisbacterial pathogen.

The foregoing is illustrative of the present invention, and is not to beconstrued as limiting thereof. The invention is defined by the claimsprovided herein, with equivalents of the claims to be included therein.

All publications, patent applications, patents, patent publications,sequences identified by GenBank® Database accession numbers and/or SNPaccession numbers, and other references cited herein are incorporated byreference in their entireties for the teachings relevant to the sentenceand/or paragraph in which the reference is presented.

What is claimed is:
 1. A method of treating chlamydial infection and/ortreating and/or preventing a disease or disorder caused by or associatedwith chlamydial infection in a subject, comprising administering to thesubject an effective amount of an inhibitor of epidermal growth factorreceptor (EGFR) expression and/or activity.
 2. The method of claim 1,wherein the inhibitor of EGFR expression and/or activity is an antibody,a tyrosine kinase based inhibitor, an antisense oligonucleotide basedinhibitor, FR18, an antibody or small molecule that targets the F-actinbinding domain of EGFR, an antibody that targets an EGFR-Chlamydiainteraction, or any combination thereof.
 3. The method of claim 2,wherein the antibody is selected from the group consisting of Cetuximab,Panitumumab, Nimotuzumab, Matuzumab, Zalutumab, MDX-447, mAb-806 and anycombination thereof.
 4. The method of claim 2, wherein the tyrosinekinase based inhibitor is selected from the group consisting ofErlotinib, Gefitinib, Lapatinib, Canertinib, Vandetanib and anycombination thereof.
 5. The method of claim 2, wherein the antisenseoligonucleotide based inhibitor is GEM231.
 6. The method of claim 1,wherein the disease or disorder caused by or associated with chlamydialinfection is cancer, infertility, osteoporosis, arthritis, Alzheimer'sdisease, pelvic inflammatory disease, asthma, atherosclerosis, chronicfatigue syndrome, chronic obstructive pulmonary disease, coronary heartdisease, metabolic syndrome, multiple sclerosis, myocardial infarction,stroke, Tourette syndrome, and any combination thereof.
 7. The method ofclaim 6, wherein the cancer is selected from the group consisting oflung cancer, breast cancer, cervical cancer, head and neck cancer,ovarian cancer and any combination thereof.
 8. The method of claim 1,further comprising administering to the subject an antibiotic, achemotherapeutic agent, an anti-inflammatory agent, an immunomodulatoryagent and/or radiation, in any combination.
 9. A method of delivering anagent of interest to a cell that expresses EGFR, comprising contactingthe cell with a genetically modified Chlamydia organism comprising theagent of interest under conditions whereby the Chlamydia organism bindsthe EGFR on the cell, thereby delivering the agent of interest to thecell.
 10. The method of claim 9, wherein the agent of interest is anucleic acid molecule, a protein, a drug, a small molecule, an imagingagent, a therapeutic agent and any combination thereof.
 11. A method ofidentifying a substance that inhibits the binding of EGFR to F-actin,comprising: a) contacting the substance with EGFR and F-actin underconditions whereby binding of EGFR and F-actin can occur; and b)assaying for the formation of an EGFR/F-actin binding complex, whereinthe absence of formation of an EGFR/F-actin binding complex identifiesthe substance as a substance that inhibits the binding of EGFR toF-actin.
 12. A method of identifying a subject as having an infectioncaused by Chlamydia or as having had an infection caused by Chlamydia,comprising: a) obtaining a biological sample from the subject; and b)assaying the sample of (a) for one or more proteins that are altered dueto Chlamydia infection in the subject; wherein altered is defined as adecrease or increase in the amount of the protein(s), and/or as adecrease or increase or change in the posttranslational modification ofthe protein(s) and/or as a decrease or increase in activity of theprotein(s), and wherein detection of an alteration in the protein(s)relative to a control identifies the subject as having an infectioncaused by Chlamydia or as having had an infection caused by Chlamydia.13. A method of identifying a subject as having an increased likelihoodof having or developing a disease or disorder associated with infectioncaused by Chlamydia, comprising: a) obtaining a biological sample fromthe subject; and b) assaying the sample of (a) for one or more proteinsthat are altered due to Chlamydia infection in the subject; whereinaltered is defined as a decrease or increase in the amount of theprotein(s), and/or as a decrease or increase or change inposttranslational modification of the protein(s) and/or as a decrease orincrease in its activity of the protein(s), and wherein detection of analteration in the protein(s) relative to a control identifies thesubject as having an increased likelihood of having or developing adisorder associated with infection caused by Chlamydia.
 14. A method ofidentifying a subject for whom prophylactic treatment for a disease ordisorder associated with infection caused by Chlamydia is indicated,comprising: a) obtaining a biological sample from the subject; and b)assaying the sample of (a) for one or more proteins that are altered dueto Chlamydia infection in the subject; wherein altered is defined as adecrease or increase in the amount of the protein(s), and/or as adecrease or increase or change in posttranslational modification of theprotein(s) and/or as a decrease or increase in activity of theprotein(s), and wherein detection of an alteration in the protein(s)relative to a control identifies the subject as a subject for whomprophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated.
 15. The method of claim 14,further comprising: c) providing prophylactic treatment to the subjectif the subject is identified in step (b) as a subject for whomprophylactic treatment for a disease or disorder associated withinfection caused by Chlamydia is indicated; and d) not providingprophylactic treatment to the subject if the subject is not identifiedin step (b) as a subject for whom prophylactic treatment for a diseaseor disorder associated with infection caused by Chlamydia is indicated.16. A method of guiding a treatment regimen for a subject being treatedfor a disease or disorder associated with infection caused by Chlamydia,comprising: a) obtaining a first biological sample from the subjectprior to or during treatment; b) assaying the first biological samplefor one or more proteins that are altered due to Chlamydia infection inthe subject, wherein altered is defined as a decrease or increase in theamount of the protein(s), and/or as a decrease or increase or change inposttranslational modification of the protein(s) and/or as a decrease orincrease in activity of the protein(s); c) obtaining a second biologicalsample from the subject at a subsequent time point during treatmentand/or after treatment; d) assaying the second biological sample for thesame one or more proteins that are altered due to Chlamydia infection inthe subject; and e) comparing the altered protein(s) assayed in (b) withthe same altered protein(s) assayed in (d), wherein a decrease in theamount of altered protein(s) measured in the second biological sample ascompared with the amount of altered protein(s) measured in the firstbiological sample indicates that the treatment regimen is imparting apositive or beneficial effect and should be continued and/or increasedand an increase or no change in the amount of altered protein(s)measured in the second biological sample as compared with the amount ofaltered protein(s) measured in the first biological sample indicatesthat the treatment regimen is not imparting a positive or beneficialeffect and should be discontinued or reduced.
 17. The method of claim12, wherein the protein is selected from the group consisting of EGFR,AKT, STAT3/5, PLCgamma, MKK4, ATR, cyclin B1, GADD45, MDM1, actin, p53,SIRT1-6, alpha-fetoprotein, apolipoprotein A-1, early growth response 1,peroxiredoxin 3, MK167 antigen identified by monoclonal antibody KI67,YWHAE, RbL1, heat shock protein 70 kDa (HSPA8), mitochondrial superoxidedismutase 2, endothelial nitric oxide synthase 3 and any combinationthereof.
 18. A method of identifying a subject as having an infectioncaused by Chlamydia or as having had an infection caused by Chlamydia,comprising: a) obtaining a biological sample from the subject; and b)detecting in the sample of step (a) methylation at specific DNA CpGsites that are altered due to Chlamydia infection in the subject;wherein altered is defined as a decrease or increase in the amount ofmethylation relative to a control, and wherein detection of alterationof methylation at specific DNA CpG sites relative to control identifiesthe subject as having an infection caused by Chlamydia or as having hadan infection caused by Chlamydia.
 19. A method of identifying a subjectas having an increased likelihood of having or developing a disease ordisorder associated with infection caused by Chlamydia, comprising: a)obtaining a biological sample from the subject; and b) detecting in thesample of step (a) methylation at specific DNA CpG sites that arealtered due to Chlamydia infection in the subject, wherein altered isdefined as a decrease or increase in the amount of methylation relativeto a control, and wherein detection of alteration of methylation atspecific DNA CpG sites relative to control identifies the subject ashaving an increased likelihood of having or developing a disorderassociated with infection caused by Chlamydia.
 20. A method ofidentifying a subject for whom prophylactic treatment for a disease ordisorder associated with infection caused by Chlamydia is indicated,comprising: a) obtaining a biological sample from the subject; and b)detecting in the sample of step (a) methylation at specific DNA CpGsites that are altered due to Chlamydia infection in the subject,wherein altered is defined as a decrease or increase in the amount ofmethylation relative to a control and wherein detection of alteration ofmethylation at specific DNA CpG sites relative to control identifies thesubject as a subject for whom prophylactic treatment for a developing adisorder associated with infection caused by Chlamydia is indicated. 21.The method of claim 20, further comprising: c) providing prophylactictreatment to the subject if the subject is identified in step (b) as asubject for whom prophylactic treatment for a disease or disorderassociated with infection caused by Chlamydia is indicated; and d) notproviding prophylactic treatment to the subject if the subject is notidentified in step (b) as a subject for whom prophylactic treatment fora disease or disorder associated with infection caused by Chlamydia isindicated.
 22. A method of guiding a treatment regimen for a subjectbeing treated for a disease or disorder associated with infection causedby Chlamydia, comprising: a) obtaining a first biological sample fromthe subject prior to or during treatment; b) detecting in the firstbiological sample the amount of methylation at specific DNA CpG sitesthat are altered due to Chlamydia infection in the subject; c) obtaininga second biological sample from the subject at a subsequent time pointduring treatment and/or after treatment; d) detecting in the secondbiological sample the amount of methylation at the same specific DNA CpGsites that are altered due to Chlamydia infection in the subject; and e)comparing the amount of altered methylation as assayed in (b) with theamount of altered methylation at the same sites measured in (d), whereina decrease in the amount of altered methylation sites measured in thesecond biological sample as compared with the amount of alteredmethylation sites measured in the first biological sample indicates thatthe treatment regimen is imparting a positive or beneficial effect andshould be continued and/or increased and an increase or no change in theamount of altered methylation sites measured in the second biologicalsample as compared with the amount of altered methylation sites measuredin the first biological sample indicates that the treatment regimen isnot imparting a positive or beneficial effect and should be discontinuedor reduced.
 23. The method of claim 13, wherein the disease or disorderassociated with infection caused by Chlamydia is cancer or aprecancerous condition.